Welcome to the forum! What adorable and sweet pigs! I'm sure you love them very much and I'm going to give you a few tips and links to help you take great care of them.
I have to ask, are you certain they are both girls? If you got your girls from petshops ten you should know that they often missex small animals. Even some shelters (like the SPCA) can accidentally missex them. If you aren't certain you should take them to a good exotic vet to have them resexed and for check-ups.
Here is a page that can help you distinguish between the sexes
http://cavyspirit.com/sexing.htm
Here is a great site to help you make a bigger cage.
Guinea Pig Cages, Your Cavy At Home I don't know if that bin you show in the picture is their housing but if it is it's much too small. You can make a bigger, better cage VERY inexpensively.
What kind of food do they get? it's hard to tell from the picture because the bowl looks like it's full of bedding. Here is a great nutrition thread and veggie list
Everything you need to know about a cavy's diet!!! READ ME- Nutrition Charts & Info - Guinea Pig Cages Forum
That bedding (corn cob?) really isn't very good. If the GPs eat it it can cause internal impactions. You may want to switch to something like aspen, kiln dried pine or carefresh instead and make sure the bedding is about 3 inches deep.
Hope this wasn't too much to throw at you al at once. but It's obvious that you are over the moom for your girls and I figured you would want to learn the best ways to care for them.