transfer software help?

So I am pretty new to the Mac stuff, is there a way to transfer my wifes operating software leopard, to my computer...mac pro, running tiger? the computer actually was running Leopard, but was missing plugs and software was not running or pulling up, I used the reboot disk but after the fact realized that I indeed used tiger software... I do not have the disk for leopard, and was seeing if I logged onto my wifes computer and ... copy hers... if so how?
any thoughts?
please that would be helpful... or am I screwed and should have never started what I did
at least every thing works now

 

I know that, I didn't know if there was a way around it, being that it did have leopard installed before.... was just seeing if there was a way around it since I have it loaded on another computer of my own

 

now that I am seriously new to macs how do I go about using that cloner, and say I do copy it, will it just paste to my hd, and take up a crap ton of space or do you know if it will just over write my software?