is a macbook air with 8gb ram enough for photo editing

I would recommend getting at least 16 GB of RAM. (A professional photographer or advanced amateur might want more.)

The Canva site recommends 4 GB of RAM. But if you look at Adobe's site, all of their main photo applications have a recommendation of 16 GB or more. 16 GB is also the recommended amount of RAM for DXO PhotoLab. There is Affinity Photo V2, for which the recommended amount is only 8 GB, but since you can't upgrade RAM on any Apple Silicon Mac after purchase, it's better to get a bit too much, than to get too little (and discover that too late).

Canva – Canva Technical Requirements

Yes, but for how long? As Mac OS updates with Apple Intelligence, you’ll find 8GB of RAM a crunch. And whether we’ll be able to opt out of many Apple Intelligence features has not been made clear—not to my knowledge, anyway.

All new MacBooks are coming with 16GB of RAM, so one has to conclude that Apple knows that 8GB of RAM is not enough going forward.

Apple no longer sells Macs with only 8 GB memory, so there's that.

Under her post says she has a MacBook Pro 13”, so I concluded she already has an 8GB RAM MacBook.