What relationship is the step-daughter of your son to you?

[callula]

What relationship is the step-daughter of your son to you?

[CheekyChops]

A step-granddaughter, surely.

[dot.hawkes]

yes correct cheekychops, I think callula was thinking there may have been another name for it, like an in-law name, but there isn't. Any children your son has with his step-daughters mum will be your step-granddaughters half sisters , and your grandchildren

[callula]

Thanks to both of you - that's exactly what I need! I thought it might be step-granddaughter, but was worried that might suggest your husband had children from another marriage (who subsequently had children of their own), rather than your son's wife. I guess it's the same name in either case!