Yes, agree with so many others:
a) get a good instrument if you can
b) get it set up properly at a good string shop - this bit doesn't have to cost much, but can make a huge difference
c) better strings
d) get fine tuners put on the end of all the strings, so you don't have to touch the pegs, and you can still tune it. Then get a tuning app on your phone and tune it each time (or teach her how)
e) open strings for quite a while, listening to the sound. It's all about bow control, and there's no need to involve other fingers (which often are what make it sound screechy). She needs to get good at being able to play on a single string without catching the others, and to change easily from one to the next (moving her elbow as well). She can play slow and fast bows, press harder or more lightly, different patterns of these - also trying to get smooth changes between up and down. We used to play the same note or sequence of open strings, but with loads of different bowing patterns. She can make up her own rhythms etc. Playing with a straight bow in between the bridge and fingerboard will help the tone a lot - get her to look in the mirror to check - often the bow will go crooked towards the end, and drift over the fingerboard
f) Hearing intervals - don't need the violin for this; can she sing what a tone or a semitone or a third should sound like? (if you don't know what these are, the teacher can show you, or you can get a keyboard - even on the ipad! - and play the notes). She needs to be hearing what she is aiming for. Ideally if she can sing them, that's great, or even if she can listen to them and be able to tell them apart. The tuning app can also help with that!
g) gradually introduce fingers, but don't use the bow, just pizzicato. And listen very carefully to the tuning! Lots of children want to progress to using lots of fingers, and quickly, but don't care about the tuning. Better to go slowly and just learn them gradually, as it's a combination of muscle memory and listening to what it should sound like, and comparing. No point playing a whole series of fingers, if they aren't starting in the right place. If you have a piano (or again, the keyboard on the ipad or something), can she play a particular note, and match it to the sound she hears? If not, can she tell if she is matching or not? etc.
h) gradually start bowing the fingered notes as well. Having quite strong fingers that can hold the string down firmly enough also helps, so lots of activities like play-dough etc can also be good, if she has weak fingers
It really doesn't have to sound as bad as that! Tuning and bow control are the things that make it sound like a screechy cat, and the more you work on those at the start, the better the sound will be. Trying to go too fast and get into tunes etc too soon just leads to bad habits. You see children who just play by 'finger number' - they know to put their third finger down or first finger or whatever, and what string to put it on, but they have no idea how to listen to tell whether it's exactly right!!