She may have wanted a D when she was heavy into the A, but if she's been dumped by OM then she could be feeling a some emotional insecurity. Some women think they just have to have a man at all times.
We have learned that cherial cheaters often find a different OM to start another A or rely on the H to be her backup plan, until she can find better. That 'could' be her reason for dragging her feet about the D papers. Pure speculation on my part.
Thriver, how long of a marriage does your jurisdiction consider a "long-term marriage" for purposes of spousal support? It's possible she may not being "emotional" about her strategy at all. Anything special kick in at 5 years of marriage, or 15 years of long-term relationship ("common law marriage")?