<human>: Give me the gist of the text in a nutshell

A little back story:

My in-laws immigrated to this country and have lived with me for 6 years.  I claimed them both as dependents the first year they were here, but then my father-in-law got a job, and I haven't claimed either as a dependent since, until this year.  My father-in-law saw a wage decrease in 2013, and as a result, they both depended more on me in 2013.  They also decided to leave the US and return home to the Philippines permanently.  It wasn't really obvious whether there would be much benefit to me to claim my mother-in-law as a dependent, and I didn't care one way or the other, but her husband told me to claim her this year.

I went ahead and claimed her as a dependent, since I provide their housing and utilities, and because he suggested it. I've already received my return. 

They both left to return to their home country a few weeks ago, but I just learned that he also claimed her as a dependent on his tax return.  ( I guess he learned that not claiming her would have left him with a liability).  Should I file an amended return, and remove her as a dependent? (I'm in a better financial situation to pay back money owed than they are).  Is there something else I should worry about?  Would it be bad to wait and see if I get audited or something similar?
<bot>: claimed my mother-in-law as dependent on taxes but learned that her husband also claimed her.  What to do?