R.C.
Oh, honey, this is so difficult, but here goes. You may wish to follow some of the advice to have a talk with her.
But, if you have and feel she is not receptive, consider this. In many neighborhoods there is a person exactly like this, a toxic personality. You are not going to change her. My suggestions are that you don't schedule walks with her and don't apologize. Just use one standard reply if she asks you why you didn't call her "I'm spending a little special time with my daughter." Do not apologize. Do not feel bad if you invite another neighbor to do something and do not include her. If it is your neighbor asking, she can include anyone she likes. If you are setting things up, you can ask or not ask anyone you like. Do not apologize. If you are with her and she asks if you are pregnant, develop another pat answer such as "I'm not talking about that anymore." Repeat as necessary. If she makes remarks to you about a friend, you, or your husband say "I am not comfortable with that." She will protest that she is just joking. Repeat "I am not comfortable with that." Do not accept invitations from her. Do not discuss her ways or her lies with the neighbors. I know this all sounds severe, but I have helped many people in this situation. Good luck and remember, not everyone has to like everyone, we just need to treat them with respect.