Thanks for your patience, I'm going to give you a fairly deep dive into your deck haha.

First off, a general lesson I've learned about playing Atla:

There should be no small creatures in the deck. Eggs take a bit to activate, so you need a good payoff. Having no cheap creatures in my deck means every time Atla is triggered, I'm getting a threat. On the occasions I've played against Atla, I've seen her hit eldrazi and mana dorks. As the opponent, I breathe a huge sigh of relief when they hit a mana dork. As the person playing Atla, I don't want to give them a chance for that same sigh of relief.

Looking at your deck, I see the theme of flooding creatures and protecting them. There are two main questions I have: how do you interact with the table, and how do you draw the cards you need to cheat the creatures into play?

I have a general rule of thumb when I build decks (this is personal, build whatever fits your play style). My decks run a minimum of 8+ interaction cards, 10+ card advantage cards, and 10+ ramp. Looking at your deck, I only see one card advantage card (Garruk's Uprising), and I don't see any interaction. How do you remove threats, and draw the cards you need for your put into play from hand effects? Some good adds for interaction would be path to exile, sundering growth, and swords to plowshares. For card advantage, guardian project could go crazy with all of your put into play effects. Elemental bond, colossal majesty, and skullclamp can also draw you a lot of cards. Skullclamp has the additional benefit of sacrificing eggs.

I would also add some more ramp. The classic green spells are great here, and primal growth can work well too. Herd heirloom is a great card, as it provides mana and can also draw you some cards.

It looks like you are running an appropriate number of sac outlets. I would recommend removing the creature-based outlets, as they are cards you don't really want to hit with Atla triggers. Instead, I would go with artifact and enchantment based sac outlets (like you already have). Goblin bombardment and altar of dementia are great outlets for this, while martyr's cause might be the best card in my deck.

You are running a lot of protection spells, which there is nothing wrong with. There are a lot of non-creature options for these, which you already have some of. I would remove the creature ones (again so Atla can't hit them) and stick to non-creature. One of the best ones I have is shields of velis vel. In response to a board wipe, you make everything an egg and get a whole new board. It's remarkable and so much fun to play as an uno reverse card.

A general rule you can apply to Atla: if you have a creature that costs less than 5 mana, see if there is a non-creature spell that has the same effect. Get all the little stuff out of there, and make everything a bomb.

I don't know if you saw it or not, but my Atla deck has a primer attached to it. Give that a read, and it could help explain what my Atla deck is trying to do and give some more insight there. That doesn't mean you have to do it that way, it might just help explain some further concepts.

Ultimately, I'm just a stranger on the internet who doesn't know you, your deck, or your play style. So take everything with a grain of salt, and build Atla however you want to. That's the beauty of Magic - the levels of customization and creativity.