Temporary foster friend for my own kitten?

Hi all. I had been planning to start fostering adult cats, but then found a kitten on the side of the highway. Sooooo now I have a kitten. However, she is too small to safely interact with my adult cat, and I think she could probably use a friend until she grows up a little. My local shelter has no shortage of kittens to foster, some are sick and should probably not meet another cat, but some just need to gain weight for surgery, or need to be socialized, and are otherwise healthy.

The shelter doesn't explicitly forbid pet and foster interactions, they just state it's not recommended and any harm to your pet is your responsibility to cover.

From what I've heard, kittens are usually pretty chill with meeting other cats, and introduction is usually fairly simple and quick. I do have a separate room to keep fosters separate in at least until introduced properly. Just curious if this is an ok idea? Has anyone had bad kitten-kitten introduction experiences?