Advice required about cat going outside.

I am at my wits end! I have two cats - both rescued as strays/ferals. One was older when rescued and HATES being an indoor cat, though we forced her to be for two years as we lived in a busy road and I didn't want her out anyway. The other has always been an indoor cat since we rescued him as a kitten from a feral colony and he isn't fussed about going outside.

We have moved to a city where the bylaw states that cats cannot be allowed off your property. We live in a quiet neighbourhood where everyone lets their cats out.
More cat escaped - she pushed the air conditioning unit to one side and got out and she also on a separate occasion destroyed a screen to get out.

As an indoor cat she was very stressed - wouldn't eat, lost fur and would vomit constantly. We tried feliway, we tried different diets and we tried toys, we tried feeding her in different locations in the house - but still she was stressed.

So we let her out, with vaccinations, collar and tag, microchip and at the recommendation of the vet but she is so friendly she keeps going into people's houses and I keep getting calls about her. Plus that bylaw exists for a reason. We could try building an outdoor structure but we live in rented accommodation and there are a lot of restrictions with space to do that.

I just don't know what to do. Well, I guess I do - she needs to be indoors again - but I just hate to do it to her.

We have three cats who have always been indoor/outdoor but we're working on getting them to be mostly indoor for their safety.  We built them a catio so they can still get out in the fresh air but still be enclosed.  I do still let them outside but only when we're home and can supervise them.  

Is that a possibility--only letting your cat out when you're there to watch her?  Or how about leash training?  How do you think she might do with a leash to go out for walks?