Tori Spelling and Dean McDermott's daughter Hattie is getting so big!

Over the weekend, the 42-year-old actress took to Instagram to share a slew of new photos of her little one celebrating her fourth birthday — and the pics are cuter than cute!

"Happy 4th Birthday to my little #HattieCat She celebrated her birthday at school yesterday and insisted on wearing designer… Her fave dress @tutudumonde & amazing Rapunzel inspired cupcakes @cassieclarkcakes LOVE YOU PRINCESS! Xoxo," the former Beverly Hills, 90210 star captioned one snapshot of Hattie posing with a birthday cupcake.

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Tori and Dean, 48 — who married in May 2006 — are parents to three other children, sons Liam, 8, and Finn, 3, and daughter Stella, 6. The actor is also a dad to a 17-year-old son, Jack, from a previous marriage.

Click through the gallery below to see more of Hollywood’s cutest kids!