@creatinglake Yep, you can. I used to follow !linux from my Mastodon account. Now I'm commenting from my Friendica account!
I will say though, following Lemmy via Mastodon isn't ideal. No downvotes, link posts mess up the "copy link to post" feature, all the replies are forced into your timeline as boosts, and you can't actually post to the forums (only reply) because there are no post titles.
@_ed You should! It has an excess of features - the thread display and post titles are the ones that make it a lot easier to interact with Lemmy, though I'm still not sure I can make link posts; but also recommended users, federation with Diaspora, following RSS feeds, dislikes, quote re-shares, post formatting, and a bunch more.
It's dated in some ways, like the signup process and some clunky aspects of the UI. But it might be better than Mastodon once you get the hang of it.