Parure
The jewelry can be worn for ages 3 and up since they have small parts that could be considered choking hazards for the 3 and under set.
Jewelry that is uncomfortable or jewelry that you make have an allergic reaction to should not be worn.
A parure. (A matching set of four or more pieces: often a necklace, earrings, broach, 2 bracelets and occasionally a ring) A demi or semi-parure is generally 2-3 matching pieces.
Sure, if you child wants to wear Halloween jewelry everyday. It's a style choice.
If you really need to know, I have no idea.
Yes. Jewelry stores have mezuzot you can wear as pendants.
Yes, moonstone and amethyst can be worn together. They are both beautiful gemstones that complement each other well in jewelry. Moonstone is often associated with intuition and feminine energy, while amethyst is linked to spiritual awareness and protection.
Whenever you wish
jewelry
The bracelet.
Ring
Jewelry sets always look great together because they all go with each other.