Can Bitcoin be recovered from a child key alone? I have a question regarding BIP-32 and keys.
Imagine a scenario in which a user creates a new Bitcoin wallet with a seed phrase. He then generates a new address and sends 1 BTC to this address.
Under the covers, my understanding is that a master private/public key will be created from the seed phrase. Then, a child key is created under the parent key for the address.
Now, suppose this user completely loses their seed phrase / master keys, BUT they somehow have a copy of the child key pair that contains their Bitcoin.
Is it possible to recover their Bitcoin from that child key alone? If so, what is the process? Are individual child keys just the same as normal (non BIP-32) key/pairs?
Thanks!
Under the covers, my understanding is that a master private/public key will be created from the seed phrase. Then, a child key is created under the parent key for the address.

That's correct.

Now, suppose this user completely loses their seed phrase / master keys, BUT they somehow have a copy of the child key pair that contains their Bitcoin.
Is it possible to recover their Bitcoin from that child key alone? If so, what is the process? Are individual child keys just the same as normal (non BIP-32) key/pairs?

Key derivation is not part of the protocol. It is simply an approach wallets use to avoid the need to store backups of every separate key generated. Old wallet software (2009-2013 era) didn't use BIP32 at all.
BIP32 is just used to turn parent keys into child keys, and then those child keys are used for signing. As far as the protocol is concern, the parents don't exist.
So the process is exactly the same with or without: you sign directly with the child key. If you have that child you, you can sign, regardless of where it came from.