Need help: British Father & Filipino Mother

I suspect that or step brothers or step sisters may be part of the problem.

Softly and slowly is probably best way forward although would be useful to have details of them as an alternative source of help although no guarantees on how react if this is family secret

thats why i suggested it,..simple old fashioned black mail.

Yep agree with the step relatives bit, what op needs to decide does she potentially want to disrupt a family for her own gain.
Skeletons coming out of the closet can be upsetting for all