Really depends how all this is going down. In a relationship, you should be -equals-... not just taking turns being slaves. If you -feel- like doing nice things for her... you should do them as often as you feel like. If you happen to enjoy doing nice things on a regular basis, it shouldn't matter what she does in return because you should be doing them out of a love for her... not out of an expectation for reimbursement.
However, the same goes for her. For the relationship to be healthy, she SHOULD do nice things for you because she -feels like it-... not out of responsibility.
One immediate conflict I see is this:
i dont feel she goes out of her way to serve me when i walk in the door.
Just because she doesn't "serve you" when, where, and how is convenient for you... doesn't mean she doesn't appreciate you or care for you. Likewise, I'm sure that regardless of how many nice things you do for her, SOMETIMES there are times when she could really use some kindness that you just plain miss... or you don't understand that she needs... or perhaps you're busy focusing on your own feet hurting.
My point is stop worrying about what she doesn't do for you... and appreciate what she DOES do. If she really doesn't do ANYTHING for you... then yes. She's taking advantage of you... leave her right now. But, I'll bet she shows you some kindness.
My second piece of advice usually is directed toward women... but it really does work both ways: Try asking. Believe it or not, your partner is not psychic. They can not read your mind. As much as you "hint" or as much as you think "they should know" ... if you really want them to know something... you have to tell them... directly. Not "hint at" ... not "imply." ... Speak. Of course, tact is a good thing, you don't need to be painfully blunt. But, maybe she just assumes you like to cook. Some people do. Maybe she just doesn't have the idea that you could use a backrub. Try asking for one.
And, not by bartering... no "I'll make you dinner if you give me a back rub" ... it shouldn't be payment.
And, as nicely as you can put it, don't order it. No "I'd like a back rub now." Because by wanting it "NOW" ... it's a chore. Maybe they're busy at the moment. Instead, try "can I have a backrub a little later" ... then they can decide when it's convenient for them. A lot of times, it'll be "now" ... but not if you ask for it "now."
... just treat them with common courtesy. Don't expect a foot rub as you walk through the door. Take a shower first. No one wants to rub gross feet.