I said "mother figure" because I remember a Gina interview where she said that and I thought she was right but that's just how
I feel about them. I can see how some people would like them as a romantic couple but to me they have just the perfect relationship right now.
Also, I see her more as a mother because she paid for Harvard and guided Harvey through his time there. I feel like she "nurtured" him somehow. Kinda like Harvey is doing with Mike.
Harvey is someone who has felt alone in his lfe and sometimes he didn't have a family to hold on to. I think he sees the people who surround him (Mike, Donna, Jessica, even Louis) as his family.