Yes you can put two females together

It requires some steps but if you follow
them correctly you shouldn't have much problems
1. When you get your guinea pig put it in a cage next to the other ones for 2 to 3 days,
this will allow them to see and hear eachother but not get in contact as it will make a difference in
meeting someone you have never and meeting someone who you know a little bit

Also make sure
they are both healthy so they don't pass any disease on to eachother
2. Time to introduce!When you introduce them make sure it is neutral ground where none of the pigs have been on, this is because of territory reasons. Put them in a play pen with a new or a fleece that hasent
been used the most (make sure it is a clean fleece) Provide them with fresh vegetables and hay so they
are distracted and don't only focus on the other pig
3. Monitor the behaviour heres a link to dominance behaviours
http://www.theguineapigforum.co.uk/threads/dominance-behaviours-in-guinea-pigs.28949/
Make sure there is no blood drawn if so seperate the pigs. Although it is very rare that sows will not get along with eachother. Introduce them for about a week
4. Scrub the cage with vinegar and water mixed together this will remove pee stains and get rid of their smell. Both boars and sows need two houses/hideys this is because some guinea pigs just dont like to share one hidey house together.... For eg. My guinea pigs like to share hideys with eachother and are very well bonded but it depends on the guinea pigs personality. Make sure nothing has the others smell on it and wash all fleece beds tunnels etc....
5. Put them together in 1 cage! You may want to still monitor the behaviour and if not already the first night put them into your bedroom so you can feel more confident about leaving them together. ( some people will seperate the pigs even if it is normal behaviour like for eg. my dominant pig honey nips at Gizi but it doesn't hurt her it's just snaping and that is normal if there isn't too much so just read the link and you will be fine
Best Of Luck
