Famora's dealt with Zest on multiple occasions before since they enjoy gardening! And she's learned that she basically has to treat them like a child, demanding they use 'please' and 'thank yous' and not helping them unless they do so. Zest, for their part, tends to spend a little time in local gardens (I like to think every town in Fluffia has at least a small community garden) every time they're forced to visit places. Not their idea of a good time but supplies are a thing and they aren't about to waste food if they grow too much for themselves and their companions.
In this particular case, Zest managed to run out of water in their watering can and when Famora offered to help got rude about it. She scolded them and didn't let Zest take the offered watering can until they were polite about it. Famora's solution on dealing with Zest wouldn't work for everyone, but they cut her some slack because of their shared interest in gardening (as a rule, it's a LOT easier to get along with Zest if you're really into gardening or animals).