Savannah Miller says watching her sister Sienna become a mother again helped convince her that she could start over with another baby at 47.
The fashion designer explained in a first-person British Vogue essay that spending time with Sienna’s younger daughter, born in 2024, changed how she viewed returning to diapers, sleepless nights and the earliest years of motherhood.
When Sienna told her in 2025 that she was expecting her third child, Savannah took the news as the final encouragement she needed. “It felt like a sign,” she wrote, adding that she and husband James “Jim” Whewell were willing to try if they were fortunate enough to conceive.
The baby will be her fourth child and her first with Whewell, joining Moses, 21, Lyra, 18, and Bali, 14.
Sienna’s Third Pregnancy Felt Like a Sign
‘I saw Sienna’s pregnancy as a sign’: Savannah Miller, 47, reveals her sister inspired her to have another baby as she opens up on her ‘complicated’ fertility journey https://t.co/ac89uFiWLZ
— Daily Mail Celebrity (@DailyMailCeleb) July 13, 2026
Savannah said the idea of returning to the newborn stage initially felt daunting. Her youngest child was already well beyond the early-years phase, and she had begun imagining the freedom that would come as her three children became increasingly independent.
Her perspective shifted after Sienna welcomed a daughter with Oli Green in 2024. Savannah found herself more patient and present with her young niece than she had been while raising her own children alongside the demands of launching the fashion label Twenty8Twelve.
She recalled feeling that she had something to prove during her first pregnancies, when work and parenting often competed for her attention. At 47, she believes she would approach the experience with more confidence, perspective and awareness of how quickly childhood passes.
Savannah also credited Sienna with refusing to accept the different standards applied to women who become parents later in life. She said her sister’s attitude helped her look beyond commentary about age and consider whether another child was right for her own family.
Savannah Is Keeping the Fertility Details Private
Savannah acknowledged that conceiving with Whewell was not straightforward. The couple tried for several years and used reproductive technology, but they have chosen not to identify the treatment or explain precisely how the pregnancy was achieved.
She said the decision was not motivated by embarrassment or an attempt to hide the difficulties that can accompany conception later in life. Instead, Savannah and Whewell believe their son should eventually decide whether the circumstances of his conception become public knowledge.
The positive pregnancy test arrived in December 2025 at the couple’s Gloucestershire home. Savannah handed Whewell a bottle of Champagne and the test, then had to explain to the first-time father that two lines meant she was pregnant.
Their baby is Whewell’s first biological child. Savannah said he had long wanted children of his own and had already become a devoted stepfather to Moses, Lyra and Bali after their relationship began in 2019.
The New Pregnancy Has Brought a Different Pace
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Savannah first publicly announced the pregnancy in March, calling the child the couple’s “longed for miracle baby.” She said sharing the experience with Sienna, who was also pregnant at the time, added another unexpected element to the family news.
This pregnancy has been physically different from her earlier three. Savannah said she began showing sooner, requires two naps most days and has relied more heavily on maternity clothing than she did in her 20s and early 30s.
She also discussed experiencing perimenopause before becoming pregnant and said the hormonal changes of pregnancy had unexpectedly restored some of the creative energy she felt she had lost.
At the same time, the physical demands have forced her to delegate more household responsibilities and accept help from Whewell and her older children.
She Plans to Slow Down After the Birth
Savannah said she intends to take more time after the birth than she allowed herself following her older children’s arrivals.
During her earlier years of motherhood, she was building Twenty8Twelve with Sienna and often returned quickly to work. In the Vogue essay, she looked back on that period with mixed feelings, saying she loved the work but now sees how hard it was to fully absorb the early baby years.
Her son is due in late August, and Savannah said she wants to remain in the newborn stage for as long as possible rather than immediately returning to her previous working pace.