Thank you for contacting Mearto with your appraisal inquiry.

It is a lovely vintage jewellery set. Based on your information it is made of sterling silver and 14 kt yellow gold. As for the stones do not think that it looks like amber - the colour and clarity is not typical of amber. I would guess that it is a semiprecious stone of some kind - however it is hard to determine based on the photos. It could be citrine stones however it is hard to determine based on photos alone.
As for the signatures of a potential maker these are to unclear to see on the photos. The design of the jewellery resembles jewellery from the last part of the 1900s and early 2000s. It is smart and fashionable.
The estimate provided is for a well-advertised specialised online jewellery auction, where I believe the set has the best chance of realising its fullest potential. However, there is no measurement for the sentimental value you might attach to the earrings and necklace. Retail "asking prices" can be higher and vary.

Please let me know if you have any additional questions. I’m happy to help.
Thank you