We had a blonde, and my husband and I had (we are grey now!) very dark brown hair. It’s possible!
Hubby and I had blonde kids although he and I have dark brown hair. But that was normal because back when we were toddlers, both he and I were blonde, too.
We taught our daughter when she was three to answer the impertinent question of “where did you get your blonde hair?” with “From recessive genes!” Funny thing, most of the interlocutors had no idea what genes were.