I have been a lurker on COTH for awhile, never feeling the need to join. But, reading your finding Pond’s gift to you in a new (sick) girl caused me to sign up. Firstly, I relate completely - my Syreino left me a wonderful gift 10 days after his death (at the age of 19) in this little feral black and white kitten (Riley). I caught her in the trap almost immediately, but she got loose when trying to transfer her to a dog crate and it took me 5 days to get her out of her hiding spot in the garage and into the dog crate. I DID NOT WANT ANOTHER cat…I just didn’t. I socialized her and took her to be spayed and then threw her in my tack room and each morning I put her in one of the stalls and brought her back into the tack room in the evening. Well, one day she decided she’d had enough and she climbed up over the stall door and out into the big world. But she came out of hiding at dinner time and three years later she is the most precious cat to me (and she clearly rules my life). Syreino knew I needed a new kitten, even when I was sure I didn’t. So, I get them finding us with the help of their dearly departed sibling.
I have a 14 year old cat that had her eye removed 6 months ago (we medically managed anterior uveitis for most of her life, but glaucoma set in and it was time to remove her eye - turns out she has occular sarcoma and without the eye removal she’d be dead by now, it remains to be seen if she develops other tumors in her left eye or brain). She has been blind in that eye most of her life, so the eye removal was no big deal to her at all (wearing the collar was a big deal and she had a hard time with that for the 10 days she wore it) and I have been assured that should she develop a tumor in her other eye, they would not hesitate to remove it as well. So, as a one-eyed cat owner, it really is no issue. Rhodes is a happy girl and removing the eye has not changed anything for her.
Do find a veterinary ophthamologist if you can - it made a difference for Rhodes’ comfort level I think through her eye issues.
Additionally, my sisters cat had similar start to your new kitten and though she never lost her eye, she had no sight and had a skin covering over it.
I wish you and Pond’s gift - Abigal - much love and happiness together for many many years.
I’ve bee making cat and dog collars with an eye towards raising money for her care, but she refuses to sit still long enough to model. 
