An old sample that is in such bad condition will have little to no value. The same can be said for any damaged item. The choice to throw out your grandmother's sampler is up to you. If it has sentimental value, or you like the funky look you can frame it carefully for your own amusement.
If you choose to keep it, display or store the old sampler away from sunlight or any bright light and away from humid locations. Use a framing mat so the textile does not touch the glass. The glass should be UV blocking. Best yet, you can take it to a professional framer who understands how to preserve old materials.
The decision to keep or toss old items of sentimental value can be difficult. There is a fine line between maintaining old items of historic family value and hoarding.