Okay this is long im sorry!!

so i recently got married to the love of my life we have been together for 4 yrs before we tied the knot now my problem is HIS MOTHER!!

He has a daughter that is 7 and i have 2 children daughter 7 and son 9. My family has welcomed his daughter in to our family a long time ago she calls my mom nana and dad pappy and they treat her just like there own. They never leave her out when they take grandkids to do something they always make sure she is involved they love her like she's one of their own if they buy the grandkids something she get something as well because she is one of their grandkids in their eyes. My husband mother on the other hand never has anything to do with my kids she will call and ask if she can take his daughter for the weekend or take his daughter to the movies or take his daughter to lunch but never asked if she could have my kids I understand his daughter is an only grandchild but I feel as if she hasn't even tried to bond with my kids we are currently trying for a baby and I'm so scared that when this baby comes it will be all about this baby and his daughter and my kids with feel left out more how do I go about addressing this issue I talk to my husband about it and he has pretty much said he completely understands where I'm coming from and his mom does need to work more to have a relationship with my kids but she doesn't when we go see her or we go do something with her she says hi to my kids and that's pretty much it and then makes it all about her granddaughter why were there she'll buy her presents and everything right in front of my kids and give them right to her my kids are starting to feel very left out and begs me not to have to go when we go see her and stuff and I'm to the point where I'm ready to just cut all ties with her.