The celebrity interior designer - who made her name alongside Laurence Llewelyn-Bowen on the BBC’s Changing Rooms - wept uncontrollably and refused to leave his side after identical charges against her were withdrawn.
Ryder Richardson, 48, was due to stand trial yesterday morning at Swansea Crown Court with husband Colin MacDougall, 46.
The couple jointly run the Manor House Wildlife Park in St Florence, near Tenby, West Wales.
In 2008, the star gave up her TV career and bought the dilapidated 52-acre zoo-cum-wildlife park with her husband.
Three-year old Gruff Davies-Hughes, from Llanelli, suffered serious head injuries at the attraction when a heavy branch fell on him during strong winds in August 2010. The boy spent three days fighting for his life in intensive care after being airlifted to hospital.
His mother suffered head injuries and fractures to her leg, pelvis and arm.
The guilty plea potentially leaves the way open for a civil claim for damages from the injured pair.
MacDougall admitted the charges he had previously denied when they were re-read to him in the dock.
Ryder Richardson collapsed into his arms as he pleaded guilty to both offences. She then buried her head in her husband’s chest and sobbed.
MacDougall also pleaded guilty to two identical charges on behalf of their joint company, Manor House Wildlife Park Ltd.
The two charges against Ryder Richardson, brought by Pembrokeshire County Council, were withdrawn. MacDougall will be sentenced at a later date.