Keep level one on uproot as is, then lvl 2 add aoe. If there is more than one building in the area then all those building will be affected. If you uproot some rook towers lvl2 it will get ones that are clumped together (then we actually have a decent hero against rook towering (i know queen and torch are okay but it is still awful). At lvl 3 increase the range and add a slowing effect to all units that pass by. at lvl 4 increase range and keep the current ability.
Making it so the ability only can be cast on building will make sure that queen does not have too many slowing skills BUT will also let her push with that ability.