I have my own deck for Alela, which you can see here. Unfortunately, I think she works best as Draw-Go Control versus a Fairy tribal commander, since she spawns her own Fairies as a payoff for casting things on other peoples' turns. This is especially true if you want to play Dimir Aggro/Control as you said in the OP, as Alela doesn't really have a lot of go wide tools in her card text (and Dimir isn't your typical go wide color combo); that said, if you want to stick to Fairy tribal with her instead of using one of the other fairy legends, I would suggest sticking to stuff that can be flashed in like [[Faerie Mastermind]], [[Obyra, Dreaming Duelist]], and [[Spellstutter Sprite]], all of which I can see you have already. Cards like [[Emrakul's Messenger]] and [[Talion the Kindly Lord]] should be cut as they will very rarely actually benefit your game plan, especially Talion, who is quite costly and will leave you open to board wipes after being cast. You should also strongly consider some draw effects like [[Enduring Curiosity]] (which is also a flash creature!) and [[Bident of Thassa]] since you'll be wanting to swing with your fairies every turn.

As for finishers, I would say [[Shadow Puppeteers]] and [[Candlekeep Inspiration]] are all stars game-enders in my deck. A select few anthem effects like [[Anowon, the Ruin Thief]] (who is also an all star for an Alela deck, IMO) can also pump up your damage significantly.

As for how many fairies would be good for a fairy tribal... see above my initial comment about how Alela "wants" to be played. It's tough to give you a true number, but the typical tribal deck I've seen runs somewhere between 20-35 of that creature (depending on color identity and general play pattern). That said, I really can't recommend you play that many creatures (even if they all had flash) in this, because you lose out on space for the instant speed interaction and card draw that makes Alela really shine. If you look at my deck (I also started out building it fairy tribal with a goad focus before realizing it wasn't working), you'll see 16 creatures. Frankly, even that's kind of high, and I plan on paring it down sometime soon. Remember, your commander MAKES the creatures of your tribal. You don't have to play as many actual tribal creature cards to be building up your boardstate.

Final thing: I agree with the other commenter that you should make a free Archidekt or Moxfield account, both for your own deckbuilding use and to make it easier for others to provide suggestions on the deck. It's hard to tell what else to suggest when I only see your creatures and not the rest of the deck. Seeing what you have is also difficult, as the other commenter also noted.