H1B to H4 COS , received I797C saying case approved , but not I797A


We had filed for my Spouse’s H1B to H4 COS 2 months back. Today we received I797C saying the case was approved , and that this is only a courtesy copy , and the original approval notice(I797A) will be sent to the mailing address on G28.

I asked my attorney, they say that I should receive the I797A also.

It has been about 10 days , and we haven’t yet received I797A . How long does it take usually ?