I think she is glad you got a second chance and are getting help but does not want the relationship. That is not the same as not wanting/missing you, just that your life and experiences are no longer compatible with what she is doing in her life. Relationships are hard work and it sounds like yours is now more one-way for her and not something she wants to work at as a relationship. I don't think she would mind an email telling her how you're getting on, etc. but I would not expect a reply and I would look for new friends more in line with your age and experiences, etc.

Before you had horse riding together and meeting in person/lunching; what do you have to offer the relationship now? Your current difficulties are lots of work for you, too, and not something she is doing now in her life. I don't imagine she's in the process of leaving her husband and finding her own way with young children or counseling, etc. What would you talk about? There's no common ground there and what you did together 2 years ago is no longer relevant/a friendship relationship binding agent any more than your husband's battering of you is a marriage relationship binding agent. The relationship has changed in such a way that it cannot be maintained without both parties working harder than usual to make it so and she has clearly indicated she does not wish to do that.