Beatrice, as far as I know, has never had gainful employment. I think the sources of Beatrice's money were the inheritances she likely received from her great grandmother, grandfathers, and grandmothers, as well as an allowance she likely received from her grandmother the Queen when she was alive and before Beatrice's marriage. On the Ferguson/Barrantes side, if she got anything, it may not have been substantial. If Sarah was using Beatrice's card, then that means she was okay with taking money away from Beatrice's future. Sure, Beatrice might have allowed it, but Sarah took advantage of her daughter.