Adult wheeled mobility outdoor walker or rollator (South Reading RG2)

My stepmother will soon be requiring a walker to venture outside of her home. She is very independent and reluctant to accept formal help. However - one of her friends has been given a pre owned walker and seems taken with it. My stepmother might just do the same. I am wondering if anyone knows of a pre owned one that I could try and persuade her to use please? Or where I might source one of these locally for her to try - preferably free! Many thanks for reading....I can collect easily...