Sealing an adopted sibling

My parents have only adult children but are currently deciding to adopt a 17yr old from foster care. The reason for adoption being so that she can be sealed to them (legally she'll be 18 in less than a year so most everything else won't matter.) In this case:

1. Would those of us who are married be a part of the sealing at all since we are sealed to our spouses already?

2. Since she is likely to get married and sealed in a few years to her spouse is there still a reason to get sealed to my parents?

This is all a very new situation to me and I would mostly like some insight while I try to process it all. I haven't actually even met her yet and it seems like a lot to me at this point, but at the same time everyone deserves a family and who am I to stand in the way of that.

Sealings generally performed in temples today are either sealing to parents, or sealing to a spouse. There's no ordinance of sealing to siblings. So, you wouldn't need to be present for the sealing. If you choose to attend, it would only be to show support to your parents and the adopted sibling.

If your parents were married in the temple, you and your siblings were likely "born in the covenant." That just means that you are sealed to your parents automatically from birth. The ordinance of sealing to parents performed in the temple provides the same blessings as being born in the covenant. Those blessings are different from the covenant and blessings associated with being sealed to a spouse. Both sealing relationships – sealing to a parent and sealing to a spouse – are necessary, whether in this life or the next, to receive all the blessings of the gospel.

If you are endowed and haven't attended a sealing to parents before (or if it's been a while), I'd recommend scheduling an appointment at your temple to attend a sealing session. You can use Ordinances Ready to find one or more ancestors who need to be sealed, or just attend and help with names submitted by others. Listening to the blessings associated with the two sealing ordinances might help you to find some peace and insight. I attended a sealing session a few weeks ago with some ward members and it was a great experience.

I would add that, although sbradshaw is correct that siblings do not have a direct role in the sealing to parents and do not need to be there, the church does recognize the special interest involved and the support a sibling can provide at this special time. As a result it allows siblings to attend the sealing in certain cases where otherwise they could not. Specifically siblings under the age of 8 can always attend. Siblings between 8 and 21 can attend as long as they have a current limited use recommend. Siblings over the age of 21 do have to be endowed to attend. Special authorization can be made for siblings with special needs who do not need baptism or the endowment. All of this is outlined in the General Handbook Section 27.4.5.

It sounds like in your case, you and your other siblings may already be over 21 so the special rules may not apply. But as someone with 4 adopted sisters and 2 adopted children, I see these rules as recognizing that although siblings don't have a formal part in the sealing, they are still part of it as it binds the entire family together.