From page 3 to page 5, her head grew three sizes that day. Seriously. Irma's head was well proportioned on 3, and mutantly large on 5. Her right arm also apparently shrunk, because there's no way there's her hand could be at 90 degrees that high up her chest otherwise. Did Irma hit the mutagen before waking up April? The rest of the current pages are fine, though.
Holy shit does this story skip a lot of context. I mean, I know we're here for porn, but if you're going to put some semblance of a story, at least make it consistent.
You can't actually tell on P5 if her elbow is at a 90 degree angle or not. If anything the angle of the wrist indicates that the angle of the arm is less than 90 degrees, because the hand is pointing slightly downwards. The arm pose is totally replicable IRL. The head tho, there is no explaining the head. Honestly her face and head is pretty deformed throughout most of it, which is weird because April's seems mostly okay. I don't know much about TMNT so I looked up the character expecting her to have crazy-defined cheekbones relative to April but if anything her face is more chubby than April in canon so I dunno where the face proportions are coming from. I'm surprised nobody mentioned P9 where she's had a full lobotomy done, based on her head shape. ¯_(ツ)_/¯