The Secret Service must be blind, but they aren’t stupid. They aren’t going to allow somebody they are charged to protect come to harm.
That is not to say that Weinstein wouldn’t try something, because he has gotten away with everything all his life and thought he might get to be alone with Malia as well.
Odds are, if she is involved, the Secret Service used their own experts to get everything on Weinstein they need.
Do a little research, her SS isn’t thee to parent. They aren’t there to tell her no to anything. They are only there to stop someone from killing her. She was drinking and doing drugs and partying hearty with questionable people when she was underage. She was doing shots at a fraternity until all hours when Moo had accompanied her to college visits. SS had to scurry her out from a party on Martha’s Vineyard before the cops raided it. The last two summers, she was video taped doing drugs at Lollapalooza.
She missed several family events/photo ops at the WH. She and Sasha were supposed to be bride’s maids for one of Moo’s assistants (and IIRC the groom was SS) but poof! nothing. Not only was that story completely dropped by the msm but the wedding itself suddenly went quiet. She was supposed to have a summer internship in Spain at the Embassy but poof! that went down the memory hole. The girls were supposed to go to Brazil with daddy for some heads of nations thing but poof! again more nothingness. There were rumors she was in treatment but suddenly Moo claimed she’d been climbing mountains in Peru. Suuuure. If Malia was in Peru, she could have popped over to Brazil. If she were merely vacationing, that shouldn’t have stopped Sasha from being in the wedding or all the other things they’d been scheduled for. But, no, if Sasha were seen then there’d be questions about Malia.