Are the children of the stepfather from another wife considered foster siblings to the questioner's daughter if the questioner's mother breastfed her daughter?

If your daughter breastfed five times from your mother's milk, which resulted from intercourse with the suitor's father, then your mother becomes a wet-nurse mother to him. All sons of your mother's husband (the suitor's brothers) become milk-siblings to your daughter, so none of them can marry her. As for you, you may marry one of your mother's husband's sons from a different mother, as they are non-mahram to you. The prohibition of marriage extends from your daughter to her descendants, but not to her collateral relatives or ascendants.