Police said thieves burgled a home in Turners Hill Road, Crawley Down, stealing rings, necklaces and earrings.
The items were commissioned by the woman with the intention of passing them onto her nine-year-old daughter at significant moments in her life.
Detective Constable Rebecca Buckley said: “The victim may not live to see these key times in her daughter’s life. These are highly emotive circumstances for the family involved and we are renewing our appeal for anyone who has any information about the jewellery to come forward.”
The burglary took place on Monday March 4 between 5pm and 7.30pm.
Police are looking to reunite the woman with her jewellery and anyone with any information is asked to report it online or ring 101 quoting serial 1064 of 04/03.