You're right, I missed that too. ina sheomra leapa = in his bedroom ina seomra leapa = in her/their bedroom Since words beginning with s cannot be eclipsed, the "her" and "their" forms are identical. When you mean "their", "ina seomra leapa" could be translated either as "in their bedroom" or "in their bedrooms", i.e. each one in his/her own bedroom - there's no need to use the plural of "seomra leapa" in this case, since each one of "them" only has one bedroom. Irish differs from English in this usage.