EEA PR - in laws of EU citizen

[CR001]

Asking on behalf of a friend of my brother.

Couple entered the UK on an EEA FP in July 2013. The couple live on the own in their own rented accommodation and both work full time. They don't live in same city as sponsoring EU citizen daughter in law.

Couple now want to apply for PR and asking if they have to show evidence of dependency on EU citizen to qualify for PR, dependency which they don't have as couple are wholly self sufficient so would not have any evidence.

EU citizen has been in UK since 2005 and non EU husband is already British but EU citizen is not.

EU citizen and husband are planning on going their separate ways and divorcing.

What options are there for the couple on EEA RC to apply for PR or any other route to remain rather than return to South Africa? What about retain rights if residence if EU citizen divorces their son?

Any advice helpful as always.

[CR001]

Grateful if Obie or secret.simon could offer any advice.

Thanks