I think those may be Aphids

There are nymphs of several different kinds of insects, good ones and bad ones, that are often mistaken for spiders. And spiderlings are extremely small, so don't discard that thought.

I'd not worry when you've only spotted two of these critters. If they are aphids, you'll soon have a zillion of them...and you are correct that they are simply too large to be mites.

I don't think this was an aphid, I've only seen two of them (1 the first day, 1 the next), there wasn't any when I looked today.
The link below is a pic I found on google, but if it was white & a little smaller it would look like this:

Here is a link that might be useful:

Spiders are beneficial and when we find them on our plants, we should leave them alone to do their job.