Applying for RC for extended family member ( sister)

[boi]

Dear all,
I hope somebody can help or direct me in the right path.
We came to Uk in 2010- My husband is dutch-I initially came on a RC as a family member of EEA national. However, shortly after getting that, my application for Irish naturalisation was approved while I was here (lived in Irl 1997-2010) so I am now Irish.

I would like to bring my sister who is non EEA and over 21 as my dependent. She is now in home country. She has visited me twice when I was in Ireland ( I paid for her and supported her wholly while she was there). She returned back home in stipulated time during each visit. In 2013 I applied for her to work in disney for a year-on a disney international program. When she finished in florida she came here for a month then went back home. Again I financed all those trips. She is now back at home and still financially dependednt on me. She cant get a descent job, The disney job could not be extended.

My questions:
1. Can I apply as my extended family member (both my husband and I are working full time since we arrived)
2. What proof of financial dependency will I need to submit? I send money to her. How many months bank statements/western union transfers will they require?
3. Any other documents that I need to get in order to strengthen my case?
4. Do I need to involve an immigration solicitor?
5. If I need solicitor-any recommendations in Leeds/sheffield area?

thanks in advance.