And to top it off, her issues with Hermione. Oh god. Helen will never be mother of the year, she's not motherly, she's never wanted to have that responsibility thrust upon her. This stems from her own broken relationship with Leda, where she refused to even look at little Helen because of what she reminded her of (which is fair enough). However, Helen wasn't a bad mother when Hermione was little, not stellar but she would've made sure not to treat Hermione how Leda treated her. Although I imagine that for Hermione being in Helen's shadow would've always been uhg. And Helen is incredibly vain and wouldn't have pushed her daughter out of her shadow.
When she went off to Troy, she did miss her, but she was also far more trapped in the politics of Troy, her husbands and the wreck she was busy causing there.
And then coming back and not recognizing Hermione...well, oops. It wasn't done out of spite, again Helen is just selfish, but she would've wanted Hermione to have a good marriage and be protected. At the same time, she'd be willing to use Hermione as a pawn... so. She's crazy, Hermione, I'm sorry.
On the other hand, Helen isn't unaware of her shortcomings as a mother and part of her reluctance to have children is that. It's not her thing, she's not going to make anyone happy. Also pregnancy is a bitch.