Help with pattern adjustments

[Viridian]

If this is posted in the wrong area, please move. Thanks!

Before I say another word, here's the pattern.

My boss wants a tea cozy for her teapot. I found a great pattern for it, called a Tea Mitten. I think I've made posts about this pattern before, but this is a whole new dilemma.

Her teapot is very odd as the spout comes straight up from the top, while the pattern is written to create a gusset at the side.

ForLife Wholeleaf Teapot.

I need help figuring out what changes I need to make for both the split for the handle and what gusset (a tiny one, as you can see) I need to do for the spout.

I did some measurements to help with this.

Teapot Height - 4.5 inches
Start of spout - 3.75 inches from bottom
Start of Handle - 1.5 inches from the bottom.

The problem for me is mostly Midsection A, as I can't tell which is for the split and which is for the gusset.

I'm not sure how complicated this question is, but any guidance would be great!