Holy Smokes! Yours is a complicated one!

Can't comment on Portugal at all. But it would be wise to have wills for each country.

A UK will covers your UK property. Perhaps a Portuguese will covers Portuguese property or perhaps it will be similar to a French will, which has some standing but will remain secondary to French Succession Law which takes precedence.

Under French succession law (regardless of a will) the French estate is divided amongst the children, with the remaining spouse at the back of the line. And the percentage of your French estate all depends on the number of "blood" children you have. If you had one child, that child would have right to 1/3rd the estate on your passing. Two children = 2/3rds, three = 3/4s. Surviving spouse gets the remainder. If you pass away it's only your "blood" children that inherit, but that includes ALL your "blood" children whether they be in France, the UK or wherever in the world.

If your spouse passes before you, it is her "blood" children (and your 2 children from your current union) that have inheritance rights to your French estate.

There are numerous complicated ways to ensure the French property goes to the surviving spouse - buying "en tontine" is one of them, but you can only place the en-tontine clause in the contract when you purchase. And the "en-tontine" cluase prejudices against the heirs of the spouse who passes first. If you have substantial French property, correct planning is critical because going the wrong route could end up with some heirs paying the exhorbitant 60% inheritance taxes when proper planning would have exempted them.

There are other ways to plan - for example, changing your marriage state. It is complicated enough as it is without the further complications your extended family presents.

Your Portuguese property is excluded from French law so you might find it easier planning to leave the French property to your 7 heirs (plus spouse) and juggling a balancing act with the Portuguese estate amongst your heirs as well.

I suspect that Portugal is more closely aligned with English law as regards wills but you really should seek professional advice because French succession law is complicated and your situation is more complex than most.

Simply googling "French Succession Law" will yield plenty of information to ponder, but you'd do well to get professional advice (and I don't mean from a Notaire who most likely wouldn't fully comprehend your more complicated family situation).