Lady Windimere was a kindly aristocrat in Sonic Underground. She looks slightly like a dog.
When Sonia's mother, Queen Aleena, was dethroned by the Dr. Robotnik of the Sonic Underground dimension, she left Princess Sonia's basket on Lady Windimere's doorstep. She raised Sonia like a daughter, spoiling her, bringing her up with stately manners and introducing her into high society, resulting in Sonia making contacts among the upper class who feared and resented Robotnik's reign.
Through Lady Windimere, Sonia met Lord Barnaby, a wealthy rebellion sympathiser, and was initially introduced to him as a possible suitor.
Her wealth kept her from being roboticized for a time as Robotnik wanted to keep the aristocrats to pay for his factories, but she was eventually roboticized by Robotnik along with Farrell and Uncle Chuck. (SSS: #10)
Since Lady Windimere is among the highest of society, it is likely that she was deliberately chosen by Queen Aleena with the certainty that she would take good care of Sonia.