Since your GF is Chinese national, she at least will not have language issue navigating TPE, which is pretty straight forward to begin with. She is also on a J ticket so that probably increase the odds that BR will try to make sure she connects. So I wouldn't worry too much about this connection. If BR5 is late, a BR rep will most likely meet your GF at the gate and escort her to the next flight. If BR5 is really really late (like unscheduled diversion late), then BR can reroute her thru a Chinese gateway (PVG/PEK etc) and from there most likely CA will take her the rest of the way to TXN. Rest assure, I don't think your GF will end up sleeping at TPE for 2 days waiting for the next BR flight to TXN.