When it came time for me to apprentice, I was a little worried that I wouldn't find a (male) farrier that would take me on because of a girlfriend/wife/gossip. But I did, and me being a female and half his age hasn't gotten in the way of anything. (Although, he did say that I can't ever meet his mother-in-law

)
I've mentioned this somewhere before and will ask again... Why should a wife or significant other have a problem with her guy having a female apprentice when most of his clientele are female, and he visits their houses on a regular basis? To me, if a farrier was going to have an affair, it would be SO easy with a client because the job site includes a house and bedroom!
If a wife is jealous of an apprentice, she's probably got some pent up jealousy about the female customers as well. Coming from a woman's point of view.