I'm not sure it will produce roots. What I would do is...allow it to grow bigger, then at some point detach leaf and plant the whole leaf, with the plantlet at an adequate depth.

Asplenium bulbiferum is a fern that produces plantlets, but this isn't it.

Yay, I think I know what it is! :)

Found pots with a sticker Doryopteris Cordata - most pics on the internet show a bit different plant, but it's close..

After some more googling and being redirected to a discussion back here, I am pretty sure it's a Dorypteris Pedata.

http://plantillustrations.org/illustration.php?id_illustration=176895&SID=0&mobile=0&code_category_taxon=1&size=0

The broken leaf dried up and the baby plant looks dead.. BUT! I've since discovered that many other leaves have tiny hairy balls..

And it's what this fern does - produce babies on its fronds..

https://toptropicals.com/catalog/uid/Doryopteris_pedata.htm

Really? well that's good to know...I wasn't aware of it's propensity, but then I've never even heard of the genus (though likely when I was in school it was a pteris, before the botanists changed all the names).