Omino Yui (小見野 結衣) from the game Kikenbi Neratte!? Haramase Gakuen (危険日狙って!?孕ませ学園). Trained for 800 steps from a variety of in-game images. Haven't found any limits on the tests, but was trained on some NSFW so take precautions if needed. Adding "loli,young" to the negative helps with body shape. Certain positions will also give a pregnant body with no easy work around.
Prompt
OminoYui,small breasts,long,blonde hair,green eyes,blue hair ribbon,twintails