She & partner can each get two Citi/AA cards for a total of 100k AA miles each, which is more than enough for two flights (check the AA award chart. Europe starts at 40k but not during August). Priority club visa would net each 60k, and using cash & points would give them 8 nights (15k pts + $60/ night) at some decent properties. Otherwise Chase Sapphire Preffered would give them each some flexible points for hotels or whatever else.