I don't think the Royal Family should respond
Megan said (and I believed her) that the HRH The Queen had been very welcoming to her and they were still on good terms. Megan said her criticisms were of the 'Firm', the Royal Household, rather than the 'Family' and she made a point that these were two very different things.
Megan admitted, then was backed up by Harry, that the comments about 'any ' babies skin colour should the two marry, was said 'very early on in our relationship'. It was an off the cuff remark addressed to HARRY (megan was not there) and probably in jest by a younger member of the royal family. When it was said, Harry and Megan were not even engaged. Megan has since used this as a weapon.
The Interview was obviously well-staged and Megan seemed to take a few random things that were said and done , take them out of context and not necessarily in chronological order, and spin them into there being some sort of Racial slur on her and Harry.
Why? What she thought being a Princess was, was way off the Mark and now she wants to be a California Princess, which is nearer her idea of what Royalty is. Harry -well i don't feel sorry for him -he will have a wife for life because if she dumps him it will be her that gets relegated back to D lister status . He will live in married bliss as he is her cash cow and source of Status.