@Background Pony #8E0D
Sure.
https://www.fimfiction.net/story/437330/1/the-sixth-alicorn/chapter-one

@Background Pony #C1EE
If you are writing a story, can you provide a link other than it?

@Background Pony #8E0D
I can’t see Chrysalis adopting a pony like Dash unless it benefits her somehow. Fully Twilight or Starlight, both of whom displayed incredible potent magic at early ages, would make better assets than a Pegasus who flies faster than usual. An alicorn would interest her even more, so Flurry Heart make for a tempting target. Then she would play “mommy” to them, hoping to convert and weaponize them against the ponies (and if that doesn’t work, drain their magic). And in doing so, ends up developing real affection for her adopted “daughter.” I’ve been writing a fanfic on a similar topic, where Chrysalis adopts Nyx from Pen Stroke’s “Past Sins” series and raises her as her own.

@Background Pony #B35B
I think Rainbow Dash’s transformation into a changeling would be unnecessary in the story. It is much more interesting if Chrysalis has to raise a pony child even though she has no idea how to do it correctly since ponies are a completely different type of creature for changelings.
And as the reason why Chrysalis has to raise Rainbow Dash, you can take the reason that “supposedly Rainbow Dash is too young to be kept in a cocoon without fatal consequences” and therefore you need to wait until she grows up. And already in the course of raising Rainbow Dash, Chrysalis begins to gradually become attached to her and at the same time learn something about ponies and stops hating them so much.

P.S. in my opinion, it is more interesting to watch how Chrysalis tries to raise a pony despite the fact that this is new unknown territory for her, than how she tries to raise a changeling since it is obvious that Chrysalis should be an expert in this matter.

@kapitantorrenton
Well, sometimes when Chrysalis is busy, her guards would look after Dashie.

Sometimes Dashie is placed in her own special cocoon, however she is let out at other times.

For this alternate take on My Little Dashie, Chrysalis turns Rainbow into a changeling (Though Rainbow would often transform into her pony form/disguise from time to time) as she plans on having Dashie become the new changeling queen when she passes. However, as time goes on, Chrysalis and Rainbow start forming a beautiful mother-daughter relationship.

And the rest….well, I’ll let you guess on what happens next.

I can’t even imagine what had to happen for Chrysalis to voluntarily adopt a pony child and it would end well for everyone.
Chrysalis already has a whole hive to feed and spending time and resources raising ponies doesn’t seem like a smart course of action.
Most likely, Rainbow Dash would simply be placed in a cocoon with some kind of life-sustaining liquid and gradually receive love energy from her.