Re: Domestic Service Visas: 1938 . . .
Make an enquiry with World Jewish Relief, the following is their website address
They have the records for 57000 refugees that came to the UK from Germany and Austria
before and after WWII., they may be able to help you.
There is also a record for Berta Heilpern on a passenger list in 1948 for a passage to New York on the website of Findmypast.co.uk