Originally Posted by
docbert
That's actually a different situation. After exiting the arrivals/customs area, the bag drop area she came to would be the "re-check" area, which is on the floor below the main international check-in area that I mentioned. They will absolutely accept bags there for domestic flights, but they can only accept bags that are already tagged - which presumably hers were not. Without them being already tagged she will need to head to one of the check-in counters in T3.
That's was the case. Because it was two separate flights, not on one ticket, her bags were tagged only to SFO and she has not checked in to her UA flight. So she has to take her cart to T3 and do bag drop and check in there.
Now, in the light of other posts in this thread, she should be instead going outside, take elevator to upper floor, check bags at UA counter at Terminal G, go to the security there as well and walk to F gates. But we did not know all this until reading this tread.