He is too high profile. people on both sides will always be looking for him. He wanted to put her in one place and then go draw attention away from her by going some where else.

She likely can’t. The New Republic’s goverment was just destroyed. Not sure Leia can suddenly go “well, i’m off to hang out with my brother for awhile, good luck!” at this point.

Why does it have to be Luke that left her? Maybe Kylo didn’t have the heart to kill her, so he left her somewhere she couldn’t be a problem. Maybe Han hid her in the Falcon during the attack and Unkar Plut jacked his ride (with the stowaway onboard). Maybe Rey’s mother took the Falcon and escaped, but it was damaged…

Han’s obvious affinity for her...