Doing sex phone work is a bit "ooh, naughty" here but as a topic for general conversation is far less offensive than in the US. We even get light hearted documentaries about sex phone operators on TV (http://steverogerson.suite101.com/my-phone-sex-secrets-chann...) featuring students and grannies who've decided to give it a crack to earn a few quid, but when set amongst US norms your suggestion is barely better than suggesting she walk the streets.

tl;dr - When in Rome..