Extension of visa refused would it affects future applications?

[RyoLi]

Hi all

My mom's visiter visa expired on April 25, 2011. we applied extension a month ago, but we just received the letter from immigration today(May 24, 2011) that refused our extension of visa because we missed on document.  (  :(my bad )

Here is my questions:

1. we bought a flight ticket that the departure date is May 30 2011. is this too late to leave? the letter says my mom must leave immediately.

2. will this affect my mom's future application to come to Canada?

3. If it will affect, would applying restoration help?

Thanks in advance