I know my feeding experience in real life has been almost non existent but i'll mention a few things i've learned of whatever type of feeding relation that might be i'm coming in with.
One thing i can mention is that money is a big factor and as much as each relationship works differently, the best way i've noticed and experimented with is that there is a fund or so much awareness of money to be spent on food which eases her guilt less and easier to gain.
I used mobile banking apps for helping to achieve this and she got to the biggest size she had ever been (still under 300lbs or so but for both me and her, it was noticeable of a change), which is probably the main success of actually me fattening someone up in this lifestyle/fetish.
Don't rely on it for long distance though, (i don't think you'll have an issue) since even if it brings a habit of daily mcdonalds, greggs/bakery, it does not always mean a gain which I've found out ended up being the opposite, especially since i've not had the chance to see her since for pandemic reasons.
But also make it a fun journey without it feeling like a gain is a chore, she might not feel that way anyway but like anything, things dont have to be at full pace, and if both makes it feel nicer when the time is spent on the binging or something like that, but its like any choices for dates
3 years