"Victoria’s son Cruz was a little star," Halliwell writes on the Spice Girls' official blog. "We all had our children up on stage tonight and Cruz started break dancing! How cool is that? It’s clearly in the family."
Halliwell's own 21-month-old daughter, Bluebell Madonna, also joined the party onstage, taking the mic and cooing at the end of the song, "Mama" after young Beckham, who turned 3 Thursday, showed off some choice moves.
In her blog entry, Halliwell, 35, also turned an eye on her band's performance: "So we've just played Madison Square Garden and it was amazing."
What especially thrilled her was that the concert marked the first one at the venue with all five Spice Girls onboard. (The ladies performed there previously – but that was after Halliwell had left the band.)
"I feel so delighted," Halliwell writes. "The energy and atmosphere were amazing."
'Sadness and Joy'As the high-profile reunion tour winds down, "I feel a mixture of sadness and joy," she writes. "I know it’s time to come home yet I will miss everyone from the tour. I love New York so, so much and I have had a blast here."
During her time in the Big Apple, Halliwell managed a full itinerary, "enjoying the nightlife, the vintage shopping, the food and the people."