Hi Bunny, welcome to Tapas!
You can only appear in the Fresh section of Tapas once per update per day, so when you post multiple times in a day, you don't actually increase your visibility on the site more than if you posted once. So that might be one reason your growth feels slow, if you're thinking "I've already posted five episodes!" when it's more like you posted two. ^^
That said, it's good to have a nice chunk of content when you start, so new subs have something to read and get hooked. Comics are all about the slow grind and playing the long game. Your concept is cute and unique, and the art is nice, so I hope you'll have good luck! Have patience, work hard, hope for the best.
If I was going to note anything, I'll just say that first drawing the the main characters as children was confusing because the boy is so large and the girl so small. It doesn't look right, and you might try resizing them in Photoshop or similar.