Am I in the wrong on this one?....?

Ok we are expecting # 3 this friday. My family lives 12 hrs away and are planning on coming up the following week to meet the new baby. My mom made a comment that it would be nice if my MIL didn't come up every night so that she could send some one on one time with the kids. (when we had our 15 mth old she would come up every night my family was here, but after they left we didn't see her for a few days) I didn't see a problem with talking with my MIL to ask her to lay low while they were here because they don't get to see the kids more than 2 times a year if they are lucky. So I asked my husband to talk with her and see if for the 3 days they will be here not to "bug" us so my family could get some quality time with the kids. His words to his mom were, "I was asked to tell you to stay away while Ali's family is in town so that her family can have time with the kids." Now she is mad. I don't feel that I am asking to much by wanting her to not smother my family since they live so far away, but at the same time I feel bad because of how my husband told her. Am I wrong for wanting my family to get some alone time with the kids? How do I talk to her to try to make things better and her not feel so upset?