Baby cannot go to V&A. Baby can go to all other Sigs and will be welcomed. Remember that these are theme park restaurants and family friendly. Not a big deal at all.
What Hibiscus said

. For reference, we are 64. "Old Farts"

. Personally? We LOVE seeing young children enjoying WDW - right smack dab in the middle of our favorite SIGS

. These are the PERFECT spots to introduce young ones to fine dinning, as EVERY WDW restaurant employee GETS the concept of children (hey, its WDW).
Now - there are suggested behavior patterns for PARENTS - not at WDW, but EVERYWHERE, during this stage. As the Father of FOUR (all grown now), I can pass on SUGGESTIONS (all personal opinion)....
1) Your child will act up

. They might not MEAN to, but they are CHILDREN. When it occurs? Trade off with hubby - remove the child from the restaurant to minimize impact to others. Often takes less than 5 minutes (though my oldest, now 35, robbed us of a good dinner in SF - threw a fit, and he STILL owes us a dinner

).
2) OK - child is currently calm. Let the child see how YOU act in a "nice place". Children learn from their parents.... and they are generally a quick study

. We saw the best behaved, most perfect 3 Year old's on our last trip (Narcoossee's, 4-25-2016). I was stunned - someone did a really GOOD job introducing them to "special" places

.
3) Trust WDW

. I have not seen ONE CM, in all these years, act as though a child is somehow a "burden". They are VERY good at dodging a loose child, entertaining a cranky child, and accepting the fact that WDW is for FAMILIES - including Children

.
4) As has been mentioned - there is ONE very serious Restaurant on property that really does not fit anyone under the age of (opinion - 16).... Victoria and Albert's. THIS restaurant is an absolute 5 star - and is best reserved for Mom & Dad's private Night out.
All of this is personal opinion....