That isn't overnight kit SLF3 its a CC bag which they have to carry with them on every flight be it over night or day trip.
The cabin crew services dictate what goes in it. The last one I saw open was truly a sight. spare Ice tongs, spare tea bags, spare tights, manuals, flight report forms, personal first aid kit etc etc.
It varies from company to company what they are required to take. It isn't an option not to have it with them. If the queen bitch finds out they haven't got it they get their backsides in a sling. I have even seen a male hostie get put on report for not having two pairs of pop socks in his bag because the CC manual stated if trouser worn two pairs of PP colour code xyz pop socks must be in your bag when he was line checked.
Thankfully that was dealt with when the Pilots ripped the piss out of it in a mixed crm course as being stupid. But the CC manager really didn't see the funny side of the stupidity and bitterly hated changing it and he was male!!.
Some nonsense that each bag was a team resource provided by the company and it didn't matter what sex you were it should always have the same contents.