This means that your great, great, great great, great, great, with about five million "greats" in there, grandmother was probably the same great, great, great, great grandmother with five million "greats" in there as Holly up here.
Esto significa que su tátara, tátara, tátara, --más o menos cinco millones de "tátaras"-- abuela, fue probablemente la misma tátara, tátara, tátara, tátara abuela con cinco millones de "tátaras" que la de Holly.