She should also consider the political atmosphere in Nicaragua right now too and all the things Daniel is doing to make life extremely difficult non-orteguistas; no work without the sandinista card, heavy CPC presence in many neighborhoods watching and listening for people "who've got something to say", police intimidation, rising local crime. While some parolees were lucky and went back without issue, others have experienced a lot of scrutiny coming back to Nic, including having to surrender a whole bunch of really detailed and personal information as part of a "census". Lord only knows what they are planning to do with all that information. It's not a good situation to go back to right now for many people.
While it absolutely sucks that her sister is very ill, I would hope she considers the pros vs cons here very carefully. She needs to think with her head and not her heart. She has filed an asylum claim stating that if she returns back to the county she will be targeted and harmed! That is a bell that once rung, cannot be undone. "No one would return back to a place with such a threat" is how USCIS will see it.
Good luck! I hope she decides to stay and see the I130 process through to the end instead of starting over. There are a lot of unknowns right now (in both countries) and there's no telling if processing times will get better or worsen.