No that is not normal that is abuse...she should not be hitting you, also if your pregnant that kind of abuse can also hurt the baby so you just might have to cut her out of your life. Do you still live with her....or do you live sepereately? But yeah if she's abusive to you, what would stop her from being abusive towards your children/her grandchildren. I makes sense you want a mother in your life and you want a grandmother in your kids lives but you cannot excuse her nasty behavior on that basis.