Baby Mama Drama

My boyfriends daughters are coming to stay with us for the summer in less than a week!! I am so excited to have them here with us. My boyfriend is good friends with the mother of his children, I don't have to worry though. There's no sneaking around or cheating, she's married and my boyfriend and I are happy and in love. I know I can trust him completely, 100%, he's never given me a reason not to. His baby mama is wanting to come with the girls and stay the night with us so she can visit family where we live (8 hours away). I have no problem with it. I know she's gonna be apart of my life as long as he & I are together, and I respect that. I don't wanna cause conflict or be in one of those predicaments where we don't get along, because that's not what I want at all..but I can't help but feel intimidated? He told her he would ask me so I don't feel uncomfortable, but I think no matter what the situation is I'm always gonna feel that way. I wanna be an adult and say yes and just try not to stress about it, but I also don't wanna say no and risk her getting mad at me. What should I do???