Best practice is to wipe the Mac & start over - that way it is impossible for your login credentials to come over to her account. It may also make sense for her to buy the desired applications in the App store too, so she can update & install them. You could tie the accounts together via family sharing, but I have no experience of that.
Apple have this generic info that may seem like overkill but it is 'best practice'
What to do before selling or giving away your Mac - Apple Support
The next option is to setup a new user account for her & delete your old one - that is less than ideal because the Mac will be tied to your Apple ID for certain things like iClouds 'Find My Mac'. If you want her to access your iPhoto / Photos library you would need to copy that over to her account first. You should probably make a list of items she really needs from your account & ask how to move them. If you go this route create a new admin user first, so her account can be a 'standard' one (running under less permissions is safer).
If you try to keep your own user account she will end up with issues where your history is used (such as saved login names in keychain access), Safari history etc. It may be OK for both of you but personally I'd rather remove the chances of old data getting in her way.
