Alternatives to Step-parent Adoption
You may wish to consider some alternatives to adoption that can provide many of the benefits of adoption, but without the downsides.
If a single family name is your key concern, you can change your child’s family name without adoption.
A step-parent can apply for legal parental responsibilities and rights towards their stepchild through the courts without having to adopt their stepchild.
To ensure your stepchild inherits from you in the event of your death make sure you have a detailed will outlining your wishes and ensuring that you specifically name each of your children and stepchildren.