She hasn't. They said there aren't any appointments as its Sunday and they said going by what's been said, it should be ok to leave her for tomorrow and she'll go then.
If your dad is going shopping, can you get some gripe water for babies with cramps? this can help to disperse any gas bubbles. You can give about 0.2 -0.3 ml every three hours max. if necessary.
Also massage/vibrate regularly. An electric toothbrush can help, if you can find a cheap one.
Take her off any fresh food and if necessary switch to syringe feeding.
A guinea pig that has had bloat is often likely to have recurring problems. When you see your vets tomorrow, please discuss this with them and ask them whether they'd let you have a "small bridging portion" at home to cover the time until you can see a vet.