As much as Gooseberry loves "real" toys (and especially the novelty of new ones) she is also and has always been the king of "anything is a toy". She'll have family drama with a set of crochet hooks, turn anything straight into a wand or sword, make a fake pineapple into a splatoon ink weapon, and find infinite joy in a bowl of beads and nothing to string them onto. The toy of the week right now is an empty half gallon vinegar jug.
Thus far it has been a nice container for items like clothespins (which I think she said was the chocolate of chocolate milk?), but most prominently it has been a trumpet and a magic water vessel. She'll parade around the house loudly humming/ooing various songs and announce to everyone when she has a new one to play[1], and then you turn around and despite having the same position on her face she is drinking from an endless supply of water.
Gooseberry has explained it thus: despite all her drinking, the water stays at the same height. She can thus drink as much as she wants to stay hydrated. It is also less filling than real water, so she can drink more of it. Occasionally elsa's magic will provide some eternal ice, but either it's not worth mentioning all the time or not always in the jug.
for the record this all began before the trumpet-themed mr roger's week we're watching ↩︎