Unpopular opinion time, but honestly Anna is really dull to me. She went from being a neat Easter egg to being a humanized Rule 63 Mr. Krabs and I can't say I'm a fan.
Fjorm may not be the most developed playable Heroes OC (I'd say she's second to Alfonse but considering he's the only one who's gotten meaningful development that doesn't mean much lol) but her voice is great and she synergies well with my main team, so it was an easy pick for me.
One of the reasons why I enjoy Fates' Anna quite a bit, especially her Supports with Female Corrin. And while Heroes Anna still has the "Gold fever" deal in the Paralogues, the fact that she's with the Order of Heroes helping protect Askr shows that she has a "good and justice" over money deal when it comes to the stuff like villages in danger, good over destruction, etc. So it's nice to see when Anna isn't all about money.
That being said, I feel the lack of interaction is what Anna suffers from, as without someone to personally interact with, all that's shown with Anna is the "mind of money" deal besides some moments like Anna's support with Female Corrin. I mean, wouldn't it be interesting to see why the Anna of Shadow Dragon has an interest in Jake?
Also, I feel like Anna could benefit in character if she had a "foil" or whatever I'm looking for. I mean, I found enjoyment when Heroes Anna kept getting messed over by the Other Anna's rule twisting when she wanted to take the pictures of the Heroes in their swimsuits or her Victory Scene in FEWarriors with the bunch of Annas trying to get the spoils from her. I think Anna could benefit from a "rival" of some kind that she gets competitive with and whatnot. One that she can personally interact with and the players can connect with.
Also, the whole Nurse Joy deal with Anna could also be expanded. I mean, that was a good part of Female Corrin's Support with her was learning why she and all of her sisters were named Anna. Not to mention you could try to have some different Annas who aren't quite the same. And we already seen sibling rivalry between them.
Either way, I don't see a problem with her and like other characters, I'd like to see IS expand on her or give her a chance to shine.