Annoying MIL

Danielle • Mama to an 8 year old and one on the way!
My MIL is always putting herself in my husband and mines relationship. I recently told her she doesn't need to be involved as we Are married to eachother and not her! After that she stopped giving her advice until recently I received a text from her...we found out we are having twins and after she got her excitement out she felt the need to text me and tell me that "I need to have as much sex possible with my husband." I was like wow! I didn't respond, because I didn't know what to say! We have an amazing sex life, but that's not her business. I need to know how Get this lady to lay off. She is divorced and hasn't remarried and is known for inserting herself in her sons relationships (it happened with my husbands brother, now that side of the family doesn't talk to her) so what do I do?? I've been tempted to put her on and help find her a new husband so she will get out of our marriage! lol any advice is welcomed!! Thanks In advance :)