introducing a single female and a pair of females?

Hello, I have a new degu Molly who has been on her own for about 6weeks (minimum) since her sister died, we adopted her 2weeks ago and shes settled in really well. There are 2 female degus who need rehoming near us who are a similar age and I wondered if it would be ok to introduce them and Molly if we decide to take them also???

Ive looked at the introductions advice and we have a big cage we could split with mesh to start it all off x