Justinguitar.com has the best beginner guitarist's course on the internet, most of which is free (in fact there is no need to buy any of the materials - his songbooks cater more for the adult male beginner - but if your DD enjoys it then do make a donation to the site as it would be sad to see this fantastic resource disappear). The beginner's course covers how to hold the guitar, basic chords, picking, strumming patterns, how to read "tab" etc and provides everything a beginner needs to get going, although if your daughter enjoys it you should also consider a class (group classes are cheap, and more appropriate for guitar than other instruments; it's a social instrument).
Once your DD can play a few easy open chords - A, Am, E, Em, D, C and G - then she can tackle simple arrangements of a huge number of songs.
Ultimate-guitar.com is the place to go for tabs and lyrics (there are also other dedicated lyric sites but the ultimate-guitar tabs will show her how the lyrics and chords fit together).
If she is petite then be careful if you buy or borrow a guitar to get an instrument that suits her size/ hands - a full-size "dreadnought" steel stringed guitar is not a good choice for a small beginner. My daughter (5'2" with small hands) started on an old 3/4 sized classical guitar and then I bought her a small-bodied steel-stringed acoustic which she still plays. Steel stringed guitars are better for pop/rock as they are much easier to play chords on (especially barre chords) and you can use a pick or fingers depending on style.
My DD started playing and singing just over 18 months ago - she wasn't a very good singer at all - with practice though she's developed a nice voice (hope it is ok to post this!):