cat sensitive skin

In September last year my cat got sick, I never knew exactly what it was, but she recovered quickly and is fine now, the thing is that they shaved her hair in the tummy to get her an ultrasonography  and I'm not sure whether it was the next day or during the next days I noticed a very little scratch just where her spay scar (from almost 3 years ago) is located, I'm not sure, I think  the shaving did that to her because her skin must be very thin there, but I didn't pay it much notice because it was very small and I was more worried about other issues concerning her health, but during the next 2, 3 weeks it got bigger because she was licking it, and I started treating her, I went through a treatment with cream and then one with a spray by 2 different vets , I also put her a type of onesie to keep her from licking, it  once got infected when I took it off to make other ones and it made contact with the floor , but then the infection stopped(they put her an injection), and I changed/change it everyday to prevent that, the wound about 2.5cm long wouldn't heal more and it always seemed moist ,it grew smaller until some point and then stopped healing. In december, close to christmas we tried with a different homemade remedy and it started to heal very quickly, I noticed the change everyday, and just about 2 weeks ago it disappeared completely, what I'm worried about is that there was nothing there for about 2 weeks and we still kept putting the remedy until this monday , we took out her onesie yesterday and today we saw that it was a little bit red again (just like it started and it will end up the same if we don't put her onesie and remedy ), probably she licked and I don't know why it happens and if she will be with her onesie forever? or is it her hair that probably hasn't grown enough? she's an strictly indoor cat,she doesn't have IFV or FeLV she just got a glucose exam and everything is fine, I wonder if her skin where her spay scar is located will always be sensitive and I don't know when to take off her onesie again, I'm just confused and I don't know if any of you have been through this before, the good thing is that she's very healthy and the onesie doesn't seem to bother her at all,she probably got used to it, but we've been treating her since september and it is hot in here now and i would like this to stop once for all, and I'm not sure how long we shall keep her with the onesie(after that little scratch heals again), thanks a lot for reading.

    Don't know the answer so am bumping for you.

Has anyone done a culture to see what type of bacteria you are dealing with?

Can you post a pic to give us a better idea of what the area looks like?

They haven't done any culture, right now it's just very little(but this is how the other one started so I'm not leaving it there),there was nothing for about 2 weeks ,but we took out her onesie she licked her tummy and it went red again, I just think that when we don't treat her and  don't put her onesie it just get worse because of the licking alone, not because it spreads but the fact that it is just in the exact same place as her spay scar and the fact that it just appeared the next day they shaved her tummy makes me think that the skin there is so much thinner and that's why it happens, it will probably heal again with this homemade remedy but after it heals how do I know when the licking won't irritate her skin again? or is it probably that since it just healed 2 weeks ago her hair needs to grow more, I'm not sure, or could it be another thing?

What are you using as a homemade remedy?

it's something my mother makes to treat wounds at home when nothing else works(and it always work) I don't really know all the ingredients ,but she uses some plants, salt and lemon, I was scared to try it on her thinking her skin must be different than ours, but since it wouldn't heal with anything else I had nothing to loose and it worked I just shouldn't have taken out her onesie, I just don't know when I will be able to do so after it heals again completely.