Not sure if dates match up but the same source I quoted earlier, Lt Browne of Wellington's staff, spoke to the Countess Gazan who was trapped when she tried to flee Vitoria. He advised her stay in her carriage until things settled down. Apparently she did not and lost one of her two children who became separated. She was taken to Wellington's headquarters where the staff treated her as well until she was sent across the lines to her husband. A determined search was made for the missing child and it finally turned up with a British cavalry regiment in the protection of a soldier who had found it wandering on the battlefield and had more or less adopted it, fed it his rations and it became a great pet of his comrades. The child was returned to the mother. Browne does not give the sex of the child.

His account of this can be seen on pp. 218-219 of his diary.

dg