This is Shizuka Minamoto fron the anime Doraemon in her 1979 version with a retro style, a keyword is not necesassry, but these are your main tags:
1girl, solo, child, short hair, brown hair, twintails, short twintails, low twintails, brown eyes, bright pupils, dress, smile, looking at viewer, indoors, retro artstyle, 1970s (style), 1980s (style), blurry background