Pictures on comps apparently have legs!

Hello,

My mom went to italy for a wedding and brought back lots of pictures! I downloaded them on her comp and they had been there for months, well the other day my brother was messing with the computer and deleted our seperate accounts and just made us a single account that we can all get into. Unfortuanately the pics are gone? are they gone for good??? Idk how to restore anything so any help would be lovely.
thank you very much!