Mint plan for US bound travelers

I'm a Mint user and my Niece from Dominican Republic will be with us for a month in the USA.

Has anyone added Mint to a visitors phone, say for a short term usage? I need her to have a US number and data plan AND be able to switch back and forth to her Dominican Plan (Claro) . There are lots of eSim Data plans out there, but most don't have a US phone number.

Has anyone done something like this, and if so was there any difficulty switching back and forth between the plans during the day?

Thanks so much for your input!