This reader asks Dear Abby what she should do about her adult children and their estranged father. Louis-Paul Photo - stock.adobe.com DEAR ABBY: My husband and I have been separated for 15 years. Our two grown children are on the spectrum. For the past two years, our daughter has lived with her father because she wouldn’t agree to be part of the team at my home and abide by the basic rules: Pick up after yourself, take your animal out, flush the toilet, etc.  Now Dad has a girlfriend, and he won’t spend any time with his daughter alone without his girlfriend. He also blames me because his son doesn’t want to have anything to do with him. Our son refuses to see him because his father beat him when he was 12. My son is 25 now, but he also blames me for what happened. Please help me understand how I can help bridge this gap. — CHALLENGED MOM IN PENNSYLVANIA DEAR CHALLENGED MOM: You cannot bridge a gap you didn’t create. You can, however, stay out of the line of fire.…