Fi, this is more about you needing to tell her something right? Is she all of a sudden going to listen and/or be reasonable? No.

She has handed over the care of SDD to you and DH and doesn't seem interested in anything further.
I think she has given you clear signals she isn't interested in any sort of relationship with you so why push it?
It doesn't mean you have to be rude or give her a sermon on "why I think you SUCK", and that would be wasting more of your time anyway.

Just don't answer the phone, or say Hi, I'll just get DD for you. I don't see the point of telling her she is rude. I don't think she gives a crap what you think anyway