''Are you sure,' Pinkie asked with concern'
There should be a question mark after 'sure'

There's an 'uncredible' in the line 'that was uncredible, Twi!' This may have just been Pinkie being Pinkie, but it lands like a spelling mistake to me personally.

'“Yep. I’m all geared up,” Twilight answered, she crouched down with her confidence coursing through her veins as she was ready to conquer the ice at full force.'
Ok, I'm pretty sure there should be a full stop after 'answered' and 'she crouched...' should have a capital on 'she'. Either that, or it should go 'Twilight answered as she...' but that would lead to a pretty bad run-on sentence. Actually, breaking that bit up into two sentences would help anyway.

Don't feel bad as this kind of stuff is really hard to completely eliminate without a pre-reader, especially when you're writing in your spare time with other demands on your plate. You've got a great response in terms of likes and people have been commenting, so your writing is obviously appealing to people; that's reason enough to keep going. I'm sorry I can't go into more detail as this kind of slice of life stuff is not my cup of tea, but I thought I'd at least pitch in with the technical side. I hate coming back to my writing only to realise there's some small, annoying oversight that colours the entire chapter.