I am thinking about it as I can have a free upgrade, but my daughter is concerned that any glitches should be ironed out first.
Many have, Floo. Windows 10 underwent the most extensive pre-release testing that any Windows OS has. Obviously, there will continue to be some - even Apple stuff has glitches during its lifetime, and it will be being addressed as and when. Mind you, what OS have you got at present?
If, as has been said already, you have a perfectly working-order Windows 7, I wouldn't rush to upgrade. You've got until July 2016 to use your free upgrade; if however, you've got Windows 8 or 8.1, most people I know are saying upgrade regardless of future glitches.