I didn't pick Molly because duh. And honestly i just picked my faves/the ones most commonly seen around here because otherwise the list would be too long.

Miriam and Tzipporah have a lot Molly-ish between the two so I can see Amalthea liking that, but Aisling is a mythical white haired being just like her and whose entire kin was s slaughtered similar to her...

She's outgoing and, not "tough" exactly in the way we tend to think of it, but enduring, I guess. Weathered enough for Amal to maybe see some of Molly in her but more optimistic, enough to keep it interesting.

^ This. Also she's warm enough to pull someone like Amalthea out of her shell (similar to what she does with Tzipporah) but lowkey enough so that Amalthea isn't overwhelmed.

I could see Tooth and Aisling getting along well with her too.

because one of them is a unicorn and one is a swan

The can be friends because they have something in common they both transform into animals amalhea is an unicorn and Odette is a swan so I could see that