A third is obviously not great, however even just looking at the responses here it's clear whether your classification is relevant or not varies.
You haven't specified what her degree is in, however maybe consider revealing it, there may be a path through that people can help with.
The door has closed on some things, graduate programmes of course will not be an option now, some masters are also now closed off. However perhaps she can mask the degree by gaining experience in her field.
So for example, I an an architect, we do not have graduate programmes and actually as we study for 6 years our degree quickly become irrelevant as we soon move onto a higher qualification and end with a very dry professional qualification a compulsory year of work experience in the middle is possible to work through regardless of degree classification I suspect etc. However, return to uni after for the next 2 years will will restricted as to which uni you can attend etc. All not the end of the world.
Her degree will define her now, but once she is at the nect stage whether that is in education or work it will become less and less important.
What are your daughters career aspirations? Could she for example live at home and offer herself for free as work experience, fill up her cv with reputable companies etc?
She will be fine however she has set herself up to have a trickier next step, how she plays that is vital.