cirno's an immortal fairy of nature I hardly think age is an issue here, she's canonically at the very least over 60.
Please take care of Cirno.I taught that child, after all.But...I didn't even hear how Cirno feels about it...Although it's not up to me to say this...-hahaha!Hakurei Reimu is being so unconfident!Be-...because...In love with Cirno.Aren't you in love?