Mother in law's death grip

I have a mother in law that is driving me nuts for the past 5 years. When I am nice to her she starts to call me 2 times a day. So then I start to ignore her and she backs off until she decides she needs to bother me again and she calls my husband crying and telling him she thinks I hate her. When my first baby was due she told me she was going to come to the hospital as soon as we had her. I told her, very nicely, that we would surely call her as soon as we were ready for visitors. she said she would come whether we liked it or not. Thus, when I went to the hospital my dad just happened to call when we were on our way and we had to lie to him. that caused a ripple effect that has persevered over the past 6 years.

A couple of years ago I took my daughters to hawaii to house sit. She found out that my girlfriends were coming down to see me. She bugged and bugged my husband until I was worn down enough to invite her as well, even though I was there for 3 months, she just HAD to come the same 5 day period that my friends were coming. Is this normal? I am at the point where I can’t stand the woman. she is annoying beyond belief. she has to know EVERYTHING about me, my friends, where I shop, what I wear everyday, EVERYTHING. I have a mother in law stalker. I screen my calls, delete emails. when she calls I immediately tell my husband to call his mom. I think his neglect for her has spilled over into my life. Am I responsible for returning her calls and coddling her, or is that the job of her 3 grown children? I can’t stand the woman anymore but I want my kids to know and love their grandma. How do I exist in this crap and still maintain a blissful, loving relationship between my kids and this insane woman?