However, not immediately... When Margo is first introduced in (92) as one of a group of three prisoners who cut Sharon Gilmour's hair under instruction from Bea, her surname appears to be Dempsey. This is the only surname left of the three given by Erica, since the other two prisoners involved are definitely (Lil) Stokes and Cavelli.
She appears again in (121) during the protests organised by Bea and Judy after Sharon Gilmour's death. Margo and Lizzie hold Erica and Meg hostage for a while in the Governor's office until they both get drunk and are easily tricked to come out.
Margo is then established as Wentworth's prison bookie, starting in (123)-(125) when her stash is a target for Judy, who wants money to support her planned escape. Margo continues her operation outside the prison when she is one of the women selected for the factory work experience (127), and tempts the factory bookkeeper Kay White to run up a huge debt. When Kay White is put inside for embezzling money to pay off her gambling debts (135), Margo first attempts to put pressure on Kay to pay up by lacing her food with broken glass (136), but it is another prisoner who eventually kills Kay by battering her over the head with a jug kettle.
She re-appears shortly before she is due for release in (179), but is back inside almost immediately when her boyfriend Wayne involves her in a payroll job which develops into a siege. Both Wayne and his friend Bazza are killed by the police. She has one episode back inside and causes so much trouble that she has to be sedated and transferred to A block (185).
But not for long. When Bea is transferred to Barnhurst, Judy orchestrates a phony conflict for the vacant top dog position to get Bea transferred back. However, Margo is given a ten year sentence for her part in the armed robbery and feels she has nothing much to lose, and declares herself top dog (198). This only lasts until Bea's return (200), even though Bea initially suffers from amnesia. She recovers her memory when Margo locks her in a store cupboard (202), but keeps this a secret from the other women. Margo gives evidence against Bea at her trial (203) after Vera has promised to have her transferred to Barnhurst - a promise that she is unable to keep. To get some protection, Margo starts to deal with new officer Terry Harrison and tapes his conversations to put pressure on him to get her booze and other goodies, but not long after she is found unconscious in a pool of blood (206). She accuses Terry of bashing her, and is put in isolation (207) but the culprit turns out to be Doreen.
Margo returns (apparently having been in isolation for about six months!) in (247) just as Sandy Edwards gives the OK for a riot and plays a minor part in it and is transferred to A block (248).
She is returned to H block in (257) and appears now and again, playing a dangerous game by changing sides between Marie Winter, Sandy and Kate. After Sandy disappears, Kate warns Margo that she is next in line for "special treament" and demonstrates by grabbing her by the throat (269).
While Carol Lewis is inside, Margo acts as her protector, as she sees parallels between Carol's situation and her own experience of being involved in a robbery with "two useless men". Margo is transfered to Barnhurst in (284), supposedly because of her gambling activities, though we haven't seen Margo operating as a bookie for some time.
Margo turns up next at the newly opened at Driscoll House while she is on the run after escaping from Barnhurst (309). She steals Meg's car, but is recaptured and brought back to Wentworth (310) at a time when Meg has already been sent to Wentworth for contempt of court, for refusing to shop Judy over harbouring Margo at Driscoll. Margo attacks Meg when Meg tells her the man she hit with her car has died in hospital (310) and she organises a bashing for Meg in (311) as she blames Meg for calling in the police. The other women treacle and feather her for this in (312). Operates as prison bookie again, but this time under Bea's control (315) as a competitor for Faye who is controlled by Joan.
When the charity concert at Woodridge is proposed, Joan tells Margo to volunteer, as she wants some troublemakers involved in order to discredit Colleen (319). Margo proves how much trouble she can cause when she leads other women in throwing boiling water over Sally Dempster when she finds out she had bashed her child. Margo's musical talents come to the fore in rehearsal for the concert (320), but she plans an escape from Woodridge, which is prevented by Joan (321). When Bea tells the women her plans to get back at Joan, Margo pretends she isn't interested because she has her own ideas: she throws a Molotov cocktail into a store room, which unknown to Margo is full of cases of turpentine (326). At Woodridge after the women are transferred there, Margo is bashed and confesses her part in the fire to the women, but not to the police (332).
After this, she disappears from the series for a while. Margo is transferred back from Barnhurst in (442), looking like she has been mainlining heroin (cut with peroxide) for a number of years. She offers to peddle drugs, but Myra warns her off. Joan is equally interested in Margo's dealing, because she suspects Margo has been transferred in order to open a new market at Wentworth. Margo then has to cope with Reb Keane, and her attempt to go for top dog position makes Myra take it up instead. The cocaine delivered by her "sister" is stolen by Reb, and Margo is reduced to running a book with Myra's approval (447). Margo is transferred to Blackmoor after she tries to frame Reb for an attack on Myra, but Reb outsmarts her by planting the evidence in Margo's own cell (448). Margo is transferred to Blackmoor....
BLOCKADE magazine gave a list of the episodes Margo appeared in. It does not agree exactly with what is given above.
Margo’s episodes were (92) to (97) ~ (101) ~ (1??) to (1??) ~ (17?) to (186) ~ (198) to (207) ~ (247) to (248) ~ (257) ~ (260) ~ (264) to (265) ~ (267) ~ (269) ~ (271) to (274) ~ (278) ~ (280) to (284) ~ (307) to (335) ~ (442) to (448)