Getting a 2nd female chin

Hi everyone!!
I've had my first chinchilla Gwenny since May. I love her very much and spend a lot of time with her and buy her new stuff every week, but I can't help but to think she could use a chin buddy. I'm afraid she'll eventually get lonely, so I want someone to keep her company while I'm at school, in work, etc. Also I think I'd really like having two of them.
I know it's possible they'll never get along and I'll have to keep them separate anyway, but isn't that still better than to have no other chinchillas around?
Gwen is almost 5 months old and the second one would be a month younger. I've heard that bonding two female chins is more difficult than two males, is there anybody here willing to share experience?
My mum keeps telling me they'll hate each other, but I think, with proper introductions, that... can be prevented, right? She's also afraid the second one will kill the first one, which has this rare colour (Black Pearl) and cost a lot of money, so...
Anyway, what I wanna ask is, is there anyone here who can tell me how do their 2 female chins get along?
And sorry if there are any mistakes, not a native speaker.