there has been no canonical storyline in the "Doraemon" manga or anime where Shizuka realizes in childhood that Nobita understands her feelings and loves her deeply while Doraemon is also present. The series mainly focuses on the adventures and misadventures of Nobita Nobi and his interactions with his friends, including Shizuka Minamoto. While there are moments of friendship and affection between Nobita and Shizuka, the romantic aspect is usually portrayed more subtly and remains undeveloped during their childhood years.
I would not be aware of them.