Hi,
I know many people who are working in the UK on FAA licences only, they all fly business jets rather than the airlines. Another thing they all have in common is experience, they have all done a year or so of instructing or air taxi, prior to getting the jet jobs.
The best bet is, if she isnt wanting to go to the airlines with minimum hours is to convert the FAA licences to JAA on return to the UK and apply to an airline like RyanAir, yes you'll have to pay for the type rating, but it gets you on the ladder.
Anything is possible, but its very hard to get the job on minimum hours, there are already a lot of people trying to do the same.
Try to talk her into doing a little instructing to gain some experience first. There are a few schools in the States that will allow you to instruct for a year after completing the course, this should mean that you could gain <1500 hours on return to the UK.
Good Luck