The actor – who previously opened up about going through IVF – shared her happy news on Instagram.
She posted a picture showing her holding her two newborns on her chest, with the babies covered by a knitted blanket.
Earlier this year, Brown Findlay had shared that she had undergone fertility treatment as she and her actor husband Ziggy Heath tried to start a family.
The 33-year-old, who is known for playing Lady Sybil Crawley in the period drama, posted a clip on social media of her injecting herself with hormones.
She also revealed she’d had four rounds of treatment, adding the hashtags “#ivf #fourrounds #recurrentpregnancyloss.”
The actor’s celebrity friends and fans rushed to congratulate her after she announced the arrival of her baby boys.
