You know, as long as they stay connected like this I don't care if it gets lewd or not.
They seem to be a bit more on an equal footing than parent and child is usually shown as. He comforts her as much as she comforts him. I would classify it more as siblings, an older sister taking care of her younger brother.
They are bonded together and love each other fiercly. They need each other and care for each other. I think that's all that really matters.