J. - CONGRATULATIONS on your baby!! I am sending you good thoughts and prayers for a healthy pregnancy and birth!
I like Helena Rose as a name. And if I had a daughter she would be named after my Grandmother too. I think naming children after people who have touched the lives of one or both parents is very special and meaningful.
My husband was very cooperative about names. I think he felt like I went through all of the trouble to get pregnant - fertility issues - I had test after test after test. He just had to fill a cup. Anyway, I think he felt like I should have the majority of the decision of what to name our children.
As for your husband not seeming to like the name. I personally think you should stick to what you like. He'll come around eventually. But you could always name her Helena Rose and then call her something like Elle or Ellie, Lena, Rose, Rosie.
My son Patrick Alan is named after my Mom (Patricia) and Alan is my husband's middle name. My second child was going to be named after my Uncle, but when the baby passed from a major birth defect, we decided to name him Elliot Christopher - which is not after anyone at all, just names we liked. Then with my 3rd child, yet another BOY!!, we went back to naming him after my Uncle, Michael Rowan - my Uncle's name is Rowan Michael - we just switched the order.
Good Luck!