yes, that's exactly what it is. i don't know when the name "sip'n'see" was formally applied but it's kind of become the official name for something that has been happening for as long as i can remember.
Where I'm from (small town in Deep East Texas), it's common for grandmothers to have them for their new grandbabies. Both my MIL and my stepmother (who live in different places) had sip 'n sees for my older daughter when she was born.
Re: Sip and see
mine did the same... had a sip and see that is.
for me... It would have to be somepin fun to sip!