Why Does She Want To Be So Involved ?

So my mother had me when she was 16 but she never took care of me basically she made my grandma raise me and thats the way its been my whole life. I'm now 21. Well , ever since she found out I was pregnant she would act so moody and cry all the time now she's okay but what gets me annoyed is how she always wants to be apart of everything like when I was having contractions and was gonna go to the hospital with my husband she insisted on going with us so she did but she basically invited herself because we never agreed to her coming. they sent me home because my contractions stopped. When we talk about buying a crib she tells us she will go with us. Also at first she was stubborn about being in the delivery room with us but I'm thankful that she finally said okay that she won't be in with us but the thing that's annoying me is today my husband jokingly told my mom my water broke and my moms like I know youre joking but dont do that because when its really time were not gonna believe you. I said " when its the real thing were not going to tell anyone " and hes like " yeah we dont plan on calling or telling anyone until the baby is born " my mom got so bothered she said she wants to go with my grandma and be in the waiting room basically she wants to leave with us in our car when my husband takes me to the hospital. 
and we dont want that at least I dont. They can wait in the waiting room but they can go in their car not with us, I want to experience all this just me and my hubby. My mom says " well what if he's at work were gonna have to take you" (she doesnt know how to drive, and my grandma doesnt drive in the freeway) so basically I told her that and since the hospital is about 20 minuets away it would be better if my husband takes me since he drives on the freeway and he drives fast. My grandma drives so slow . But my mom still insists its okay like um ima wait for my husband cause i'm not about to give birth in the damn car !! why cant she respect all of our decisions? why does she all of a sudden wanna be so involved in everything? Like , I know its her first grandchild but still -.- its annoying like back off you already had your own kids and you never even took care of them yourself so if you werent a good mother what makes you think youre going to be a good grandmother (i'm not trying to be mean but it's true) .