Am I wrong for resenting my boyfriends daughter who stole from me?

[Reno512]

I have lived with my boyfriend for 2 years and he has an adult daughter who is 28 years old and has a 3 year old. She is going to school out of state and asked to stay with us for 4 weeks. We agreed, but only to 4 weeks (after giving it a lot of consideration) she originally wanted to stay for 6 months.  I work from home, she is not neat ( putting it mildly) and I am, she is loud and has a toddler and a cat.
Her stay ended up being for 10 weeks. At about 5 weeks, I found that she had gone through my personal belongings and took something. I knew this because she actually used this item on a daily basis and right in front of me and her dad.
I didn't know how to handle it, because I was so shocked that she would do this. While she was staying with us for 10 weeks, she didn't ever offer to contribute for groceries which I pay for, she didn't offer to help with dinner that I cooked every night, she didn't do her dishes or pick up after herself or her son. I keep a tidy house and this was such an uncomfortable situation.
I spoke with her dad and he decided to confront her and she lied to him and said she didn't take the item (he saw her with it too).  My personal item showed back up in my closet, intentionally ruined the next day. I was so hurt and angry. When I tried to talk to her she was angry, defensive and rude to me this continued for her last 5 weeks with us.  I would have to go work at the at local coffee houses because if I was working she and her son would be loud, sing, make excessive noise and not care that I was working ( which includes making many phone calls). It was a horrible experience and when she left I feared she had taken other belongings of mine with her.
Her dad and I had a hard time (that's putting it mildly) working through this and it caused a huge rift in our relationship.  I refuse to let her stay here anymore, I don't want to spend time with her and I am stressed and it shows. The stealing was one thing, but the disrespectful behavior toward me for 5 weeks was unacceptable. She made my life a stressful mess. I don't know if I will ever feel the same towards her.
Sh's coming to town this weekend and it brought up all kids or feelings. Quite frankly, I have no respect for her. We opened up our house to her for 10 weeks for free. I cooked and cleaned and shopped for her and her son and when she left, no thank you, no good bye, nothing. Will I ever get over these angry resentful feelings? I love my boyfriend, but his daughter is an adult and I feel he should have held her accountable and made to leave when she began her childish, disrespectful behavior toward. I hated coming home or leaving our bedroom.
Any advice or suggestions on how to move forward and let go of the anger that I feel?

[specialmom]

I don't think you are wrong to resent anyone who steals from you.  Clearly stealing is not right. But, you are trying to be in a relationship with someone who has a daughter.  Is he supposed to cut her off because now you have a big problem with her?  That would be really unfair to even suggest or ask.  So, you put him in a position of over and over choosing her or you.  That's difficult.  I'm not sure a couple can ever be a family with that dynamic going on.  

[Reno512]

Thank you for your response. I don't want him to cut her off, but I wish he had handled it differently. I feel tht he should have made her understand that her behavior toward me was unacceptable and he wouldn't tolerate it. So, I feel some resentment towards him too. He repeatedly told me he wasn't going to let her stay after the incident (she had several  friends she could have stayed with) but, then for 5 more weeks he never had the conversation with her.
I always had a good relationship with his daughter prior to this (with all of his kids actually) and I just feel like it will never be the same now. He is in a difficult situation, I know because I have 2 kids and I can't imagine. But, this I know: if one of my kids  stole from him or treated him disrespectfully he wouldn't tolerate it for a minute and I wouldn't expect him too. He would ask them to leave, I have no doubt.
Thanks again for responding, it's nice to have somewhere to vent. It's difficult to keep this bottled up.

[specialmom]

One thing to think about is the situation she is in.  This person you were close to was that desperate to steal from family.  She has a child.  It's difficult to not look at it as a person with a lot of problems and I know if it were my child, I'd see it more that way than the surface situation of the stealing.  I understand where you are coming from but when you are emotionally connected, you care on a deeper level.  You may have gotten along with her but were not emotionally connected.  Her dad is.  And that's the difference and something that you will never be able to overcome.  He will always be her dad and feel for her, good times and bad.  And in all honesty, there would be absolutely nothing my child could do that would make me turn my back on them.  It doesn't mean I condone the behavior, but as emotionally attached as I am, I try to understand what drove the behavior and get them help.