jonel:

Is the latency you are experiencing, between the audio and the video?
That is, the bar that is being highlighted in the video is either ahead of, or behind the audio?
I don't find that to be the case when I use BIAB's "Save as video" button.
Perhaps you just need to do some tweaking in the Options > MIDI/Audio Driver window.

Also, you may want to do some research into the "process" you plan to use with your granddaughter.
The videos that BIAB produce have a fairly large file size, and depending on how you are planning
to "send" them, there may be a size limitation if you're going to "attach" them, say, to an email.

If you run into a limitation there, you might consider just creating an MP3 file from BIAB,
plus create a PDF file of the chords, also from BIAB, and send both of those, rather than a video.

Good luck!
LLOYD S