Bi-Lingual Cochlear Implant Users
Recent published studies demonstrate that some implanted children are learning two spoken languages very well. Successful bilingual learners demonstrate some characteristics that your daughter, Danielle, shares, including very early age at implantation, good speech perception skills with the device, and exposure to rich and complex models of the two spoken languages. The latter is a critical factor, and because your family is multi-lingual, you are able to provide Danielle with excellent language models.
My advice is that your family speak both English and Russian to Danielle, as you have been doing. From your report, it is clear that she is learning both languages, so let her be your guide on this. Just be sure of two things: Utilize good techniques of clear speech and language modeling with Danielle, as you would with any child who has a hearing loss; and, carefully monitor her growth in both languages to ensure that she continues to make progress at an acceptable rate.