I mean, many WGs have boyfriends and even husbands, so I gather it can work. Personally though, it'd be a challenge.
A former WG? I *think* I'd be OK with that, provided she didn't have any lifelong STDs as a result. A current WG would be a lot more difficult. Even if I could convince myself that it was really just a job for her, and she got regularly tested, I would be forever worrying about if she had caught something asymptomatic since the last test. I like to kiss. I don't like to use condoms in longterm romantic relationships. I also like peace of mind. At least a couple of those would come into conflict.
That's not to mention the prevalence of mental health issues among escorts, the substance use, how you would introduce her to your family and mates (be upfront or forever worry about her being outed one day)...