How till the 35K threshold work for Tier 2 dependants?

[sevka]

Greetings,
I was granted ILR last year and I was on Tier 2 at the time. My wife is still on Tier 2 dependant, and she will earn the right to apply for ILR in 2018.

I could not find any documents that mention the rules for Tier 2 dependants applying for ILR after the 35K threshold kicks in. My wife is self employed but she is not making 35K, she may even not make anything a whole year.

So when she applies, how will the rules work? Will it be my income they'll be checking? Since she is a dependant, I'd assume she would not have to make money, even if she has the right to do so.

Any pointers to documents would be much appreciated. I'm sure there are many others in the same situation out there.

Kind regards
Sevka