Re: when using male shirts on female Sim it looks horrible
No I'm not ignoring that. I speak in general terms and there are some men's clothing that some women can wear without it looking bad but it isn't true for all men's clothes. I clearly don't know about you personally but I have seen average sized women that could wear most clothes from an average sized male teenagers (late teens) wardrobe without too much difficulty. Trousers of course would need considerable shortening of the legs as an average woman's height is about 165cm while a male late teen would be about 180cm but if it was low cut jeans it will probably look alright on a woman. For some other kind of male pants it wouldn't look as good.
I'm in no way trying to tell you how you should dress that is up to you and if you should happen to be underage then your legal custodian as well. You are more than welcome to suggest that the developers create versions of male oriented clothes that will fit a female Sim better. If enough request it they may just do that.
Interestingly the average height of US citizens are 3-5CM (Female/Male) shorter than European counterparts. I don't know if it is related but the average US citizen also eats about three times as much fast-food as their European counterpart.
Happy gaming and I do hope that you find something that will fit your female sim better at least until there hopefully are made a conversion of that shirt you like.