Adjustment of Status - I-485

My wife (US citizen) and I filed i-130, I-485, I-765, I-131 on Dec. 5th 2014. I got the fingerprint done about a month later and i also received a RFE to add a sponsor because her income were not sufficient. But Early in January we got into a big argument and she sent a letter to withdraw her petition ( i-130). I checked my status online last week and my application is denied because she withdraw the petition. I confronted her about the situation, she said she did it because she was angry and mad at me because i direspected her. She confessed that she did it purely because she was upset. she knows that we are in love, we met in college and have lived together since. In the letter she sent to the USCIS she said that she believes i married her for the purpose of obtaining a greencard, which is not true ans she know it. She is sorry about it, we are in good terms and we are about to refile concurrently. My question is:
1 - Does she have to write a letter to explain the reason why she withdrew her first petition and send it with the new application?
2- what are the risk we get denied?