Your vet should give you 'what happens next' info.
The important thing is that she doesn't get too 'licky' or fussy with her stitches in the first few days especially. So use a buster collar if she is looking like she wants to pull at them.
The vet may ask you to go back in 10 days or so for stitches out, or they may use disolving ones.
Also, walks short and on a lead for the first few days. We tend to feel sorry for our dogs coming out of an op but they hardly seem to miss a beat so keeping her calm may be the biggest challange.
And yup its a routine op and especially with young slim dogs they are done in a matter of minutes.
If she isn't already chipped, you might like to ask the vet to do that while she is having the op so she wont even feel that.
Sometimes dogs have a little cough for 24hrs after an op. This is because a rubber tube goes down their airway while they are under and therefore sometimes the throat is a little irritated for a day or so afterwards.
The vet should also give you painkillers and/or antibiotics (depends of practice) for her for a few days after her neuter.
I know its really anxious when she goes in, but be happy that you are saving her from womb infections, and increasing protection from certain tumours in later life. As welll as helping her be happy and not frustrated :)