I read that they need a grieving period but when I spoke to a breeder she said that IHO leaving them alone can also be a bad idea.
Our Guinea pigs were two girls and they went everywhere together. The dominant one has died and now that she's alone, the remaining GP just doesn't seem to know what to do with herself. She is eating fine, however. Dd put her toy GP in her cage and that seems to have soothed her somewhat.
If we introduce another one would sooner be better than later?
I'd go for it asap. Just make sure you let your remaining girl choose her new friend as not all GPs like each other.
When my Scruffypig lost his best friend early last year, he was completely lost and withdrawn and actually lost some weight. I managed to track down a couple of baby boys at a rescue but Scruffy ended up on his own for 4 weeks before he could go to choose his new nephew. Gingerpig gave him a new lease of life and within a few weeks he put all his weight back on (and a bit more). Those 4 weeks felt long to me and must have felt endless to him. Find a friend Asap for your girl.
Sorry to hear of your loss. I agree with Fernie, if you're happy to continue the cycle of piggies and the one left isn't really old, a new friend sooner rather than later is the way to go. We lost GP when on holiday last year and remaining piggie was so miserable we worried she'd survive. We found her a baby girl - very scatty and boisterous and at first Mollie was what is THIS. But once they'd both settled and got to know one another it worked and has really given Mollie a new lease of life. Believe she'd have pined away without madcap Sadie !!! (As i type this M is 'washing' S)
Our GP1 was alone for 6 days when GP2 died GP3 was alone for 6 days before he got his girls (he had to side-by-side for a month but could still chat)
When our boars were alone and grieving ( the waiting time was the time we had to wait for their new pigs to be available) they slept in DD room at night. It was one of the things when they were alone in the day (we put them in the Pighouse as it was familiar)
Has your breeder got any suitable hogs for you? Or would you go for a neutered boar? (Boars are snuggilicious , we got GP6 after GP3 died. Our girls had each other but missed their boar , as did DD) It is so when they head for The Bridge, especially if it's out of the blue.