Is the number of رضعات (breastfeeds) and satiation considered when applying the Hadith: "A suckle or two do not affect fosterage by breastfeeding," bearing in mind that the breastfeeding occurred when I was eight months old, and I used to be left with my grandmother from 6 PM until 10 AM?

The five prohibitive sucklings require that they be satiating. The meaning of satiation is the occurrence of five sucklings. The definition of a suckling is determined by custom, such as when the child takes the breast into his mouth, sucks from it, and then leaves it. The hadith "One or two sucklings do not prohibit" means that more than that would prohibit. However, the hadith of Aisha (may Allah be pleased with her) clarifies that the prohibitive suckling consists of five known sucklings. Prohibitive suckling is not established by doubt, and the default is the absence of suckling.