I haven't made sky mom and i dieted the real thing (i am talking about sky's mom) and when it was dieted i could not even say that i dieted it and it would be easier to make sky brother than her mom.
you can use polo and just edit it as needed, which is much easier than making it from scratch
you can get sprites from here:https://sprunki-mod.fandom.com/wiki/Sprunki_Misfitmix_Remastered