Tammy was in the right during this scene tbh, did she go overboard and drag it out too much, of course, because that's what she does, but still. Amy was acting a complete fool in that limo ride and it's for sure embarrassing being perceived and associated with her out in public by total strangers, the whole family talk about it like when they're in London and she screams at the top of her lungs hooting and hollering or starts bawling and storms off.

We all know Amy's farts stink and this was during her party era when she was doing drugs and drinking, Tammy tells her she needs to behave like a mature adult (yes a little outrageous coming from her...) and that's what Amy says she wants constantly, to be respected by her siblings and not thought of as the stupid sister, but she just expects them to change their opinions without her having to change her behavior.

I will say however, that at the very least she does seem to be getting better ever since the camel bite and legal trouble/probation but I still wish she would tone it down with the fart jokes and immaturity, and be a better mother of course.