Street sign erected and intruding into the path of a 92 year old blind womans path by 33 inches in her private property her g

This sign was erected and clearly imposes on this ladies garden path, which is her own private property by 33 inches, nobody spoke to her about it, she never gave anyone permission to do so and whoever planned and put it up could not of been unaware that they had done so. Kathleen holland is her name my aunty 74 bullsmoor lane Enfield En3 6tn is the address the house number is 01992762931. My name is kevin (nephew) kevinhickey63@hotmail.com We want this sign removed immediately if she smashes her head on this the situation will get a lot more serious, registered blind and 92.