My sister-in-law has requested a french oven for Christmas but I need help on sizing. I love my basic black cast iron dutch oven but the size isn't marked in quarts. It's 10" dia. x 4" high. Would that correspond to a 5-1/2 or a 7-1/2 quart Le Creuset French oven? If anybody has one and could check I'd really appreciate it as I'm ordering on line (hopefully from the outlet sale!).