My sister said she only has an Indonesian long form, nothing about the Embassy issuing one. She said it's not in English so you can't read her only long form. I'll have to check again as you seem more knowledgeable than I.
The old U.S. passport is the proof of U.S. citizenship she needed to obtain a new passport. The COLB was irrelevant.
I'd wondered if that was the reason but, silly me, since 9-11 I assumed security would have been a little tighter (since she was only about 18 months old when they cam back to the US and 32 years in between.) and they would have required additional documents. But, as I said earlier, I'm not very knowledgeable about all of it.