Domestic Adoption of Twins

Hi Good Day!
I have a 5 year old adopted twin sons, with a written consent and endorsed by their biological mother last 2011. However, we have not worked out the legality of their adoption until now. I would like to consult the following queries with regards to my case:
1) Can we still process the adoption even though we already secured their birth certificates, with our names as their parents?
2)Is it still advisable for us to process the legal adoption considering that we already secured a birth certificates for them?
3)If to process the legal adoption, will the biological mother needs to be contacted or to be found for the legal proceedings? How about if she can no longer be found?
4)Will the written consent be enough as evidence for her unwillingness to raise the twins?

Hope you could help me clear out some information regarding this matter. Thank you & God bless.

Carz BC

do you mean you falsified their birth certificates? this will open you to prosecution of simulation of birth. there is a pending bill in congress granting amnesty. wait for it to become law.

if the written consent is notarized, it can be considered, but better if she can appear in court or at least to the dswd case worker.

Sir thank you for the information. God bless po!.