The first one sounds right. She had strong feelings for...not "to". :lol:
But, I wonder about the use of "his husband". Do you mean "her husband"? :?: That would be the case for most situations. "His husband" would imply she had strong feelings for a man who is married to another man. That is certainly possible, of course. But, just be sure just what you are trying to say. ;-)
I was trying to help Ostap77 with the grammar and meaning of the sentence presented. The morality or acceptability of such a situation is a separate matter.