The phrase "hard I know is always at last" is not a common expression, and its meaning may vary depending on your grandmother's context. However, it might suggest that challenging or difficult situations tend to be resolved or overcome eventually. In other words, the difficulties we face can often lead to growth, learning, and, in the end, a positive outcome. Your grandmother might have used this saying to encourage perseverance and patience in the face of adversity, emphasizing that hard times are temporary and can lead to valuable life lessons.