On 18th February 2019, to Matilda (née Culme-Seymour) and Joseph Trivelli, a son, Peto Emery, a brother for Elsa and Orlando.
There were previous announcements for Orlando Jack (born 2016) and Elsa Peto (born 2013), both placed by Mrs Bennett. No engagement announcement is immediately obvious to me. The mother's maiden name is quite unusual, and so I assumed she was a scion of the baronetcy of that name, but could not locate her within it's collaterals. A search of the group shows me that Michael Rhodes had a similar problem with a Rupert CULME-SEYMOUR in 2006.
What I have found by working backwards:
Matilda May CULME-SEYMOUR, born 1981 Q3, Westminster, mother's maiden name: PETO BENNET (Ancestry has mis-transcribed - check original image or FreeBMD)
I initially thought she was a progeny of the marriage between Keith SEYMOUR and Christine A PETO, 1977 Q4, Sutton, however more searching discounts this. Another probable children of this marriage:
Georgina Elizabeth CULME-SEYMOUR, born 1979 Q3, Westminster, mother's maiden name BENNETT
When I search for her in the Telegraph, there is an engagement:
Mr J.H.Q. McNeilly and Miss G.E. Culme-Seymour
The engagement is announced between James, son of Dr and Mrs Harry McNeilly, of Coleshill, Buckinghamshire, and Georgina, daughter of Mark Culme-Seymour, of West Bexington, Dorset, and Caroline Culme-Seymour, of Kensington, London.
Last updated 8 years ago
Placed by Georgine Culme-Seymour
This is then followed by announcements for 3 children, the eldest of which was placed by "Mrs Bennett".
I then found a marriage:
Mark A CULME-SEYMOUR and Caroline E P BARROW, 1978 Q4, Kensington
A check of thepeerage gives: Mark Anthony CULME-SEYMOUR, born 1942, illegitimate son of Angela Mary CULME-SEYMOUR and Robert HEWER-HEWITT.
Angela Mary CULME-SEYMOUR (1912-2012) is the aunt of Sir Michael CULME-SEYMOUR, 6th Baronet, and had been married 4 times (none of them to HEWER-HEWITT).
Still not sure about Caroline BARROW/BENNETT/PETO BENNETT ... is she the "Mrs Bennett" placing some announcements?