The satin pillowcase just about saved our lives, lol. My children hated satin caps, many brands never stayed on overnight anyway, and I'm sure one brand started to aggravate their hairlines and thin the hair due to the elastic.
I spray my sons hair with distilled water + aloe vera juice/gel, made fresh daily, kept in fridge for the day, and made in small amount, 2-4oz. After moistening his hair, in sections, I apply a light layer of Camellia Seed Oil and then a light layer of a natural hair gel like Aubrey Organic's, and a tiny touch of shea butter blend on the ends, and I smooth that into his hair, twirl the curls in the very frizzy section, and then let it airdry. My son gets super frizzy hair on his crown, the curls there EXPLODE and become very dry. And, for now, that method has helped.
However, I'm not sure you'd want to use gel with a 2 year old, as it'd have to be one super extra natural gel like KCCC
and that's expensive. I can't see that 16oz $25 jar lasting more than a week in my house, lol, but with the $7 shipping this month it might be worth a try. And, shea butter can be very heavy. I use it in whipped form, and like a dime size amount or else my son's hair gets greasy look or feeling which his father hates. Too much of the oil + gel + shea butter would equally a lint and dirt collecting nightmare.
Maybe try Camellia Oil after you apply your light leave in or whatever. It's not heavy, a little goes a long way, and it made my kids hair so soft and helped retain moisture so well. I hope it's not a humectant like Castor Oil, in that it draws moisture from hair in dry climates, but it's been working well for us even in the dry winter.