Family or Visitor visa for my mum for birth of my baby?

[ikalee31]

Hi Guys and respected Gurus! Really would appreciate a bit of guidance for you as my situation is a bit of a twist.

1. I am a Russian Citizen

2. I've got a retained right of residence till 2017 (in the form of a family member of an eea national document/visa)

3. i live now with my partner (British Citizen) and we are due to have a baby at the end of March 2014

Question: I'd like to invite my mum for 3-4 weeks for when our baby is due. She will need to present a lot of paperwork in the consulate and so will i if i really want her to be here.

****Should i send an invitation letter just from me or should me and my partner both invite her?
****Will my retained right of residence status somehow affect the consulate's decision to grant/refuse visa?
****We live in a 1 bedroom flat but will be able to accommodate my mum in here- will this be sufficient or will i need to provide other proof of accommodation for her?
****I will be in the process of applying for Permanent Residence from next week and will hardly have any originals on me. Can i just send copies of bank st/bills etc?

Any advice will be much appreciated.
Many thanks in advance.