Open Adoption Advice Sought

Hello We adopted two little girls from our local Children's Aid. They were adopted at birth but came to live with us by 3mos. The intent was to have an open adoption with birth parent contact through letters, calls and visits on a regular ongoing basis. With our oldest, K, who is now 11. Her birth mother had contact with us for about 5 years and then decided that it was too painful for her and cut back to phone calls only. K does not want phone calls but a return to her in person relationship and has refused to talk with her by phone. She is coping as well as can be expected. Our youngest, E, who just turned 5 is the one with whom we have concerns. She was the 5th child of a drug addicted mother with a long history of petty crime. Her mother gave birth to her and left the hosptial the next day AMA to seek drugs. E was temporarily placed with her father's sister while the paperwork was filed for her adoption. We briefly had contact with this sister at the transfer but that stopped within a month. None of the other family members who have adopted her previous children would contact us. Neither parent despite several visits set up - ever showed up. At 5, E has suddenly noticed this lack in a big way and has become mildly obsessed with the issue and developing a fantasy life about her birth parent which is not anywhere close to the reality. She wants to know why her mom would not want to meet her- what was wrong with her? She is having nightmares about this Any advice on what to say to her or how to proceed would be appreciated. Her mother is back in jail - should we contact her through her probation officer - CAS has washed their hands of the matter and were not very helpful at any point. Strange to hear about so many birth parents who want connection and we have offered it twice to have it rejected in both cases. Thanks John Lunman