Bobby and Christi Shepherd were aged six and seven when they died while on holiday in Corfu in 2006.
Last year, a bench was unveiled, on Queen Street, Horbury, in their memory.
And now money donated to the Horbury Village Partnership group by their mother Sharon Wood has paid for CCTV to monitor the area surrounding it.
Horbury councillor Janet Holmes said: “Bobby and Christi’s mum gave Horbury Village Partnership some money before they left the area, to help us improve the town.
“It’s they that have provided this CCTV really and we are thrilled to bits.”
Sharon and the children’s father Neil Shepherd said Bobby and Christi had spent many a happy hour of their childhood sat on benches along Queen Street “eating fish and chips and watching the world go by”.
Coun Holmes said it seemed only fitting to invest the money in cameras there, after an increase of anti-social behaviour by youths and pub-goers in the area.
She said: “There has been damage to the grass verges, brickwork and the garden on Queen Street. We have had problems with youths throwing stones at shop windows.
“And every night there seems to be people congregating around the memorial bench. It ends up filthy and surrounded by litter and takeaway boxes.
“We hope that the CCTV will mean that if there are any break ins or any serious vandalism or damage we will be able to identify and penalise the culprits.”
The CCTV was installed two weeks ago.