Most likey that is not the case. Titles pass with the eldest son. The second eldest of a titled man even pretty high up is usually not royalty let alone his youngest daughter. Even a king's grandchild may not be royalty. I have several such connections in some of my roots. However, just because you are not titled should not reduce your appreciation of a glorious lineage. I find it thrilling to read about my ancesters in books. I am so bursting with pride about some Scotish ancesters I seriously concidering buying some kind of tartan. This would have been way out of the question a year back.

Happy Hunting, your quest will be well worth the back-breaking work it will require to verify your claim. No one is going to help you much. This is your fight. I can put you on the right path. You need to verify EVERYTHING on this side of the water. That will be the easy job. France is just WAY behind Canada in web based genealogy. Do you read French? You will need to, for the next part, or be prepared to pay dearly to hire someone in France. Or find a very dear French speaking friend that you can "rope in" for a few hundred hours of work. This will probably change in the next decade or so. There are several French based genealogy sites that are comming into their own. Many countries like Brittan make a lot of money providing information. It stands to reason other governments will follow suit.

During stage one you may locate a distant relitive that might help you. I suspect there are many things amiss with your legend, there usually is. I also expect that it is not completely wrong either.