Hi! I wanted to do an outline of this image of my cat so I can paint it. Im using procreate to do a really rough outline but the two sections giving me paused are the ones circled in light blue on the actual image. Hopefully I've put this under the correct flair and subreddit.

She has a browner patch under her chin, I want to be able to differentiate her head from her neck/torso area - because shes raising her head up they kind of blend into one and the browner patch is the only thing that sets them apart. Will this come across if I include that brown colour in the painting or is there anything else I can do?

Similarly at her cheek where it blends into her body, I can see the very edge of her cheek has a finer, light gray highlight. Is the best thing to do here include very fine lines that colour? Will it be obvious that that's the end of her face and the beginning of her body?  

Additionally, not perspective related, with the mouth area, she has noticeable lips but how do I draw these without them coming out like human or fish lips?😅 Does the way ive outline them look okay or is it better to, when it comes to painting it, do a very minimal shape and not define them too much?

I intend to use gouache to paint this. Its been a while since ive painted and I never had a lot of skill to begin with, but i have a rare day off work so thought id jump back into it!

how would I distinguish these two areas?