how long to wait for child's SSN?

We applied for my son's passport, record of birth abroad and social security number back in February. We've received the first two but not the third. It wouldn't be an issue except I need it to get the tax credit on my taxes! I called the Edinburgh consulate (where we applied) and left a message but I thought I'd check here too - how long have yall had to wait to get a child's SSN?

With my daughter it was long enough that I had completely forgotten about it.

I think it can take about 4 months.  But calling is definitely the right thing to do!