Don't have to
Ugh. Looks like I need to get her Snow Leopard before any other updates…
. Scroll down to The quick-but-techie way. My instructions let you use Terminal instead of getting another app though.
I just did the following on 24 iMacs, works great.
You need to change one number in SystemVersion.plist, it's located in System/Library/CoreServices
In Terminal type;
cd /System/Library/CoreServices then hit Return (space after cd)
sudo pico SystemVersion.plist then hit Return (space after sudo and pico)
It will ask for a password, when you type the password it won't show anything typing but it is going in, then hit Return.
You will have to use the arrow keys to navigate. Arrow down to;
Not the one above it;
Under <key>ProductVersion</key> change 10.5.8 to 10.6.8. To do that, using the arrow keys move the cursor to the . after the 5, hit Delete, type 6.
Type control-O then hit Return which will save the changes. Then type Control-X to exit.
You're done, you can install 10.7 or above now without having to install 10.6.8 since the installer will think it's 10.6.8.
You probably won't be able to install anything new until you upgrade the RAM though.