A FlyerTalk Posting Legend
Join Date: Sep 2009
Location: Minneapolis: DL DM charter 2.3MM
Programs: A3*Gold, SPG Plat, HyattDiamond, MarriottPP, LHW exAccess, ICI, Raffles Amb, NW PE MM, TWA Gold MM
Posts: 100,417
Part of the answer surely is how long mother can stay on her entry permit or visa. The limit could be thirty days or less, depending on her passport and other travel documents.
There could also be maximum stays for some discounted airfares.