Adding Class Levels to a Fey Creature

[Palanan]

The PCs in my campaign have several tagalongs to their group, including a liminal sprite (https://www.d20pfsrd.com/bestiary/monster-listings/fey/sprite/sprite-liminal/) whom they’ve befriended. She has limited combat utility, but one of the players is very attached to her and there’s some good RP going on.

I’d like to add a level of sorcerer, and the fey bloodline seems like an obvious choice. My question is, can I simply add the basics for a first-level sorcerer (BAB, saves, additional spells, etc.) or do I need to go through all the ability score adjustments as recommended in the Bestiary?

[ngilop]

You can just add a level of sorceress if you want. Just hand waive those are the rolled stats.

It makes it easier on you after all and the players are not going to be upset that you short cut created an NPC.

My only suggestion would be to look at other bloodlines such as arboreal or verdant, but that is just because they is a little too on the nose for me.