Our Daughter Had a Twin Sister We Never Told Her About—On Her 18th Birthday, My Husband Brought Out a Chest He’d Been Building for 18 Years

Not dramatically.

Just enough that it does not become forbidden.

Tell Chloe when she is old enough to begin understanding.

Then tell her again differently when she grows.

Do not make birthdays memorial services.

Do not erase Elena either.

Ask for help.

Grieve together sometimes.