How can my mother find out who her biological mother was?

The state is Pennsylvania, the year 1946, she was aparantely adopted by her biological father's sister. This is kind of a soap opera story since her biological father could never let out that he was my mom's real dad since the woman who gave birth to my mom was married and it was an affair. My mothers name was changed at the time of her adoption. We do have the adoption papers but her birth records are sealed. Funny thing is the adoption records claim she stayed in an orphanage when in truth we have photo graphs of her biological father's mother (her grandmother) carrying my mom at around 3 yrs. old. and the adoption didn't take place till she was 5. It is said that my mother's biological mother was married to a famous politician who couldn't afford to have his name ruined.
I hope this isn't too confusing... but please can anyone help?

Tracking a biological parent is a difficult and time consuming project - I got lucky - found my mom in 9 months of concentrated searching. I did this back in the 70's, before internet - so today it should be much easier, and less costly.
ALMA (is on the net) was my greatest 'ally' in this quest - and back then, involved letter writing and phoning.
Good luck to you - nice that you have so many facts to begin with.

If you know what her name was prior to adoption and have an idea where she was born you can go to the county vital statistics offices in those areas and request her birth certificate. Don't mention the adoption.

You need to hire a private detective specialize in this area. But then sometimes it is like opening a can of worms... you may ruin her.