Lifestyle tips

By being on Fantasy Feeder, feederism seems quite normal. But in the real world it is not. Most people do not want to be fat or fatter. You can bring it up to her, but you might upset her or freak her out. Once she knows you want her bigger, she may be more likely to stop any gaining or encouragement.

Then maybe don't tell her everything and just stick to admitting you love her belly and wouldn't mind if she'd let herself go a little?

You know ... baby steps?

Just keep the food coming. If she enjoys over eating at all, some added weight will come naturally. And if you focus on her fat while making love, or even just when cuddling, she'll get the idea you're turned on by the softness of her flesh, hopefully making her more accepting of her body being overweight.
And if she gains, something that will increase your sexual libido as her weight moves up the ladder, she'll very likely enjoy the added attention and realize she can get away with really letting go.

you are probably fucked. I can't get most gfs to get into it. sorry