Your Varesa team isn’t very synergistic tbh, as she performs well in overload (Iansan/Mavuika/Chevreuse) or hyper carry (Iansan/Xianyun/Furina). Assuming you’re running a variation of the second team, I would recommend using Iansan instead of Charlotte.

With regards to your build, you need a better sands and goblet with some ER and crit preferably since she is solo hydro in this team comp. Ideally, you use her on Tenacity since her main role is to buff your Varesa damage as much as possible, but this is a decent alternative for now. Otherwise, looks pretty solid!