Thanks for the replies.
It's almost a $2k bill. Should I ease into it via 2x<$1000 payments or just do the whole thing in one shot? Has anyone actually had an issue with this?
NO!
What you are suggesting is a little too close to structuring and serves no purpose other than to get you in trouble. Banks and investigators are not generally stupid.
FWIW, I pay all of my wife's credit cards from my bank account and have for several years. Of course, it being my wife, I suspect that it may be a slightly different situation. Personally, I would not be comfortable using a non-family-member's account to pay off a credit card. It just seems like too many things could go wrong. Have them send a check (they can use bill pay) or use Amazon Payments or something.