That's really helpful.
So they were separated when she was just over 4 weeks old then?
Hopefully she isn't pregnant, but I do believe that females can get pregnant anytime after 4 weeks of age, so she is right on the edge of it being a possibility.
But I am not an expert.
I'll tag
@Wiebke for you because she has loads of experience and will be able to give you a definite answer.
Hi! Sows have their first season between 4-6 weeks of age, so she is right on the cusp of that, and there is a chance that she could be pregnant; if she was close to her first season, the presence of boar hormones could have triggered one. You are welcome to open a support thread in our pregnancy section for any questions and updates and read our guides at the top, so you know what to look our for.
https://www.theguineapigforum.co.uk/forums/pregnancy-baby-care-and-sexing-no-breeding.11/
Apart from putting your little girl on a good, balanced diet with lots of different nutrients and NOT overfeeding her on pellets (about 40g per day is fine), there is not much else you need to do for now. The healthier and fitter mommy is, the healthier and fitter any pups - that is the most important aspect; but you do want to have ideal sized babies for a smooth birth, not big whoppers that can get stuck during birth. Incidentally, your little girl will profit anyway!
https://www.theguineapigforum.co.uk/forums/pregnancy-baby-care-and-sexing-no-breeding.11/
Recommendations For A Balanced General Guinea Pig Diet
Any SMALL tweaks to her diet during the last quarter of any pregnancy are there to bolster her body, but do not be tempted to overdo it. With a good general diet, most needs are actually already taken care of.
Online advice has got somewhat out of hand as everybody has over time upped the recommendations trying to do the very best for their piggy, and incidentally achieving the opposite by losing sight of the fact hat pregnant mums need the whole package when it comes to nutrition, not just a few extras! The temptation to overdo any extras is just too great for many worried owners.

If she is pregnant, you should know in about 6-8 weeks, when her pregnancy will become obvious; that is also the time when you can start supplementing.
You also have to wait until any baby skeletons have calcium in their bones to get a reliable scan result, which is again around 6-7 weeks from now if you want confirmation that way.
Until then, I would concentrate on keeping your girl healthy and happy. Please make sure that she is correctly sexed.
https://www.theguineapigforum.co.uk/threads/sexing-separating-baby-boars-and-rehoming-babies.109391/
All the best for a smooth recovery of your boy! Good that you did have the eye seen promptly before it could get worse and ulcerate visibly. Eye injuries can deteriorate very quickly, with the damage not yet visible in normal light and without a special dye. Thankfully, with the right treatment, eye injuries also tend to heal pretty quickly and smoothly.
Here are our post-op care tips:
Tips For Post-operative Care
Please be aware that the little baby in my avatar, my Tegan, is the surprise legacy of a supposedly safe over 5 weeks post neutering op boar (not one of mine), just to prove the point that while rare, it can really happen as late as that! I have since heard of more cases. Good British rescues all practise now a 6 weeks cut-off for introducing neutered boars to sows, and there haven't been any reports of pregnancies for years now, despite several hundred boars being neutered in the meantime. If there were, it would make the rounds like wildfire! This is why we are following the practise of recommending a full 6 weeks post-op wait. Until then, you can keep your two piggies side by side with interaction through the bars, so they are not lonely or depressed and their bond will not be broken.