I would suggest you bring plenty for your kids to do. The wait could be long. You don't want them acting up, getting too impatient just as you are about to meet the author.
I've only been to a few book signings. The first was Jane Fonda. I expected her to be really aloof, give us the entitled, star diva treatment. She was actually warm, down to Earth, gracious & funny. She looked spectacular for her age.
Tyler Florence's book signing had a huge line. I think some people were waiting well over 2 1/2 hours. He was really warm & friendly. Stood up & took pictures with people.
Then there was Craig Ferguson. . .
I waited an hour & a half for Craig Ferguson's book signing of his first book. I had always thought he was so funny on his late night talk show. He turned out to be a dismissive S.O.B.

Then about a month or two later on his show, he had on author, Lawrence Block. Block asked Ferguson how he liked the book signings and Ferguson said he HATED doing them, having to sit there and meet all the people.

He said he wasn't going to do it again if he wrote another book.
I got rid of the book soon after that. After meeting him, what I had missed previously watching him on his show, (his arrogance,) became obviously clear to those know to
look for it. He goes on ranting tirades all the time, especially about how Barry Manilow won the Emmy over him. (They were in the same Variety Entertainer category.) He loathes the Emmys now, like they OWE him an Emmy and he deserved to win over Manilow.

He tries to make them sound like jokes, but they are not.
One time he went off into an Emmy tirade, and was so gone,

he didn't remember who his guest was that night: Alec Baldwin, who had won about 3 already. Baldwin, later, good naturedly ribbed him about it, but even he knew Ferguson had been serious in his loathing of Emmys.
When Ferguson's second book came out, you bet I did not stand in line for it, or even read it.

I have no intention of wasting my time on someone who doesn't appreciate us.