I am so, so sorry that this has happened to your lovely DD (and you) 
This has been a catastrophic system failure which sadly will be traced back to ridiculous bed pressures, targets and pressure on staff from management to empty spaces ready for the next elective patients, coupled with incompetence by the nursing staff due to numbers being reduced and junior staff given roles far beyond their competence.
Your daughter's complications will be investigated, but as you know, are discussed at consent as a potential risk of the surgery.
What is not acceptable is a lack of adequate observations by the team, a lack of senior review pre discharge in an obviously uncomfortable patient.
The beyond shoddy post op advice 
I implore you, when you are ready to, please complain. We need the help of data from such horrific incidents in order to help us put mechanisms in place to stop this happening to anyone else.
You can make it as official or as legal as you wish, but give yourself time to get through this first.
If you can, try and make a timeline of events, add to it each shift if possible. Just facts.
It honestly breaks my heart that this can happen, I have several surgeons in my family and often, the lack of a reliable, capable nursing staff to support them nowadays is terrifying.
Sending lots of love and strength to you both, please keep us posted x