Unless she has a really good plan to turn things around very quickly, then I really don't see the point in Hidalgo staying in the race. Doing so otherwise will - unless we're seeing a serious case of polling failure - only further damage her image and that of the remnants of her party. She was always a curious choice of candidate given the general field: given that Macron is the incumbent and that there was always going to be a Green candidate, what exactly is the purpose of her candidacy? Other sorts of PS politician could maybe justify themselves under these circumstances, but not her sort. There's no room.
Hidalgo should have waited for 2027, with open seat, Mélenchon rejected after three defeats and with Olympics visibility.