Her and her husband proper grammar

I am editing the following sentence, and having an issue with identifying the proper pronoun. “Her and her husband’s journeys and careers have allowed them to travel extensively.”

I know the rule about taking away the other subject to determine the proper pronoun, and if I do that here, it’s clearly “her”. Her journey, her career. However, I just can’t shake the feeling that “she and her husband’s” just “sounds” correct. I often get this feeling about a sentence (and usually I’m correct), but can’t put my finger on the grammar rule that would back up my “feeling”.

Also, in this sentence, it seems almost as if “her/she and her husband” is being used as one unit or singular subject. If this is the case, should not “journeys” and “careers” also be singular?

Any help would be appreciated. I’m kind of going around in circles on this sentence.