I have few question that bother me a lot. Much appreciated if anyone can help.

1)A person who married to a EU member who is a qualified person in UK for five year now. During the 5 years, she had 4 years of Tier 2 visa and 1 year of Resident Card as EEA family member. Can she get a permanent residency now as EU family member route?
2)Does having a Residence Card (under the EEA regulation) invalidate current Tier-2 visa? can RC and Tier 2 co-exist?
3)Can a person apply to Tier 2 Extension visa(3 years extension after the first 3 years) when she is married to qualified EU memeber? or she HAS to switch to RC (under the EEA regulation) ?
Many thanks!