me and a friend share out steam libraries and while she does own vermintide 2, it doesn’t show up as a game i can download for some reason, note that she did get the game for free when it temporarily went free in early 2022.
VT2 free weekend likely falls under the category of “free-to-play” game licenses as described in the Family sharing FAQ, so that’s probably why you can’t.
Hm, I’m aware with Free-to-Keep promotions there can be some limitations e.g. not being able to earn Steam trading cards. I’m not 100% certain, but there may be a limitation with library sharing due to it being free-to-keep. In any case, please check your DM’s!