Welcome! Thank you for your question.
That is a terrific advanced question to ask. If you marry and your wife has children then they would not be included under the typical legal definition of children that would be used for a trust. However, if you adopted the children then they would be your legal children and would be included under the definition in the trust. Please beware of a couple of points:
If you adopt future stepchildren and later divorce from their biological parent then the children are still you legal children and inherit under the trust.
Also, when you adopt stepchildren then it makes you and your spouse their legal parents and their other biological parent is no longer considered their legal parent. This can effect the biological parent's will or trust agreement.
I cannot provide you with legal advise. I can provide you with information about the law related to your question. My answer, and any information that you can find online, should not take the place of having a detailed consultation with a lawyer in your area to advise you regarding your specific issues.
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