Don't cook for them, clean for them or spend your money on them. They're not your kids, let your SO deal with them. Your SD is clearly entitled and ungrateful so stop giving her the ammunition to act that way towards you. You'll be a lot happier, trust me.

sadly alot of us deal with that crap. It is so annoying. I try my best to ignore and I would encourage you to do the same.

My SD12 has to always be "special" for attention...she does the sick thing.....the I won't wear anything but this one shirt thing.......she never likes the food offered and has to have her "special" made...but then we catch her eating the stuff she "didn't like".....at first I was trying to be nice and always set aside her "special" whatever the hell it was....but that has since stopped....no more plain noodles set aside (mostly b/c she isn't a toddler) and no more special requests....she also doesn't sit at the dinner table with everyone else b/c she has to have her "special" seat at the bar....

I ignore her and while I cringe so bad inside watching my DH act like this is all normal.......I mostly act like she doesn't exsist besides a polite hello and goodbye.

Killjoy15 is like this.  I think SpecialAccomodations would be an apt nickname for her.  She needs an exception 100% of the time.  I stopped cooking for her, then I stopped eating with her.

She can have her special meal all by herself.

My wife does this crap. It's infuriating. The kid eats butter spaghetti noodles every single day. Nothing else.

One day, my wife had to work late, so she wasn't around to make the butter noodles. I told the kid that I wasn't making them, that she could eat as I ate.

She sat at the table for 2 hours. I caught hell for it.

on nights the skids were here years ago. DH didn't believe me that they would turn their nose up at it if I made it but eat it if he made it. I said fine, prove me wrong. So I made dinner without them seeing and DH claimed he made it. They ate it. DH made dinner without them seeing and I claimed I made it. They had problems with it. They also like to feign illness when they get to something they don't like. They are fine and suddenly they have a stomachache or headache, or something, and they are terrible actors so it's pitifully comical to watch them fake it and DH buy it.

I like to cook and bake and I had made them some really cool bday cakes and such but if they are going to be so picky I'm not gonna waste my time and goodwill.

Read some of my older blogs. Exact same behaviors. Lots of good advice in the comments on them. 

I disengaged as much as possible and it's been better. The kid is still awful, but it affects me less and is directed at me less. 

SD20, when she was 15 was a pescatarian, to the point of EVERY time we made a meal or went to a friends house had family dinners, she had to ask "whats in this, is there any meat in this?"

But yet she NEVER helped me chop/prepare vegetables. It was so annoying to watch then SO prepare her special meals so she "could eat". One time, later, when she was 17 or so, I told her point blank that she would be helping me cook dinner that night. Point blank she replied "sais who?"

"Sais me".

And she did, but when it came time for something with meat, I let her not participate, but she sure as heck chopped veggies. I love cooking and so does DH. I could have taught her so much. broth making and herbs and different spices, to make vegetarian dishes taste great. But, no.

So guess what? Because she is lazy and its "too hard" and "too expensive", she eats meat now. According to Munchkin (who loves my food and helps me in its preparatation and I am more than happy to coook for her anything that I know she really loves...)

Which pisses me off because when it was everyone else catering to her, fine and great, but when that ended - convenienly switched back to meat or whatever.