She's quoting £50 extra for bareback on top of her £100 ph rate, and that is by no means uncommon. Do a search for WGs offering bareback and 64 profiles appear in Wales alone. Personally I think any punter having bareback sex with a WG is crazy, but clearly there is a market for it.
However this profile may be a PG scam, as she says to contact her only by phone but no phone number is displayed.