My goose is from April, too. She started laying in October, when she was little more than 6 months old.
Both my pet geese started nest building behavior around a month before their first egg was laid. They'd pick up sticks, hay, leaves, even carpet fluff and carefully put it down to either side, all the while making throaty sighs and saying "Kaaam-chat!" Sounds like they're trying to say "Kamchatka", but I'm not sure. Geography is probably not their strong side.