"I was given my Lola back in October and I absolutely love her. I was told she is about 4 years old.
Can I bring in another baby/young guinea pig to keep her company?"
It's never too late to introduce a single pig to a new friend. In fact, many older pigs respond more positively to a younger companion - with their smaller size, an established pig is less likely to view the newcomer as competition or as a potential threat to their social standing. Of course, that's not to say that pigs of similar age or size won't get along. Like people, bonding depends more on the individual pigs and their personalities. You never know who may hit it off.