Officers are appealing for witnesses as the incident happened in the daytime in a busy area of the city.
Detective Constable Sarah Fox said: “The victim has been left distressed and upset by this burglary especially as they took jewellery that was of great sentimental value to her and even stole from the moneyboxes of her grandchildren.
“I’d appeal for anyone who saw anything suspicious in the area at the time to contact me." Anyone with information is asked to call DC Fox at Shirley Police Station on 101 or call Crimestoppers anonymously on 0800 555 111.
More top news
Thursday's weather for the west of the region
Thursday's weather for the east of the region
The RMT union has accused Southern of inventing figures which the company claims show record numbers of guards are going sick.