The mahram relationship is not established if there is any doubt about the number of breastfeedings

Praise be to Allah.

As there is some doubt about the matter, and you do not know whether it was five breastfeedings or four, or less than that, then the basic principle is that the mahram relationship does not exist. As that is the case, there is nothing wrong with this marriage, and this breastfeeding concerning which there is some doubt is not considered to establish the mahram relationship.

And Allah knows best.