If it is near the top, tell her to empty the tank till the water line is an inch or two below the leaking seam. Dry the area then apply silicone and let it fully cure for a day or two. I did that to my 15 gal and so far no leaks.
If the leak is coming from the bottom half of the tank, I'd ditch it if it is cheap. I wouldn't risk a leak coming from the bottom.
Currently out of the hobby
Forum lurking every now and then