There we go in english (my best english, any way):
"I spent this summer in the country; I am staying in this moment at general Andreony's chateau rented by Bayard (the name Juliana gave to Stroganov, comparing him to the french heroe). Bayard's wife is very sik this summer with no hope of geting better. She will stay in Dresden during winter with her daughter. Bayard spent six weeks with her but now is coming back: he knows that his presence and the continuity of his attachment to me make my hapiness. I have with me a young girl, daughter of a person he met before going to Spain. It's a very good company for me, and (Stroganov) deserves that I take care of her and make her worthy a man which she ressembles so much. Her name is as nice as she is: Idalia"
This letter was sento to Julianas's sister, Frederica, in Portugal, writen in french.
I think this prooves that Idalia was no Juliana's daughter. I dont know exactly where was Grigory Stroganov before being ambassador to the court of Spain, and nothing about Idalia's real mother, place ant date of birth. France is a meer guess.