I'm sure you have enough experience and nothing to worry about. You'll do just fine despite any weight or size differential (that's differential ...
not "disadvantage").
I love BBW's * and all full-figured fems. I've always said women should always be at (or even a bit above) their "recommended" weight that's healthy for them. Scrawny, underweight and toothpickish women are not only unattractive (and in some cases, sickly) but are open to all types of negative health issues. We live in a society that glorifies women 1 step away from anorexic physiques, imho.
So just relax and whatever the hell else you both do ...
1)
NO smiling ... giggling ... laughing or
too damn much blabbering during the event.
2) Keep the action constant and steady (I mean ongoing). You can always move from fast-paced to slow-paced and vice versa but avoid lull's ("downtimes") ... if you take a break, tell the digicam operator to turn it
off ...
then resume.
3) Avoid spending too much time on dumb-ass moves/positions like arm and leg pulling/twisting; putting your foot in her back (backbreakers) and crap like that. (Who in the hell watches that bullshit anyhow ? ? ?

)
4)
Be competitive but work "together".
5)
Go full-blast and
Have a blast.
BBW takedowns just require an application of simple physics. You have more mass/weight than you might be accustomed to so target the center of balance close to the ground and just use more force and speed to effect overthrow. Translation: go grab the lower legs (close to ankles) and use your own weight with enough speed (mass x velocity = momentum) to push/pull to overthrow. So just practice it
before videoing it !!!
So I'm sure you'll both do fine !!!* ... that are well-proportioned. You get some of these BBW's who are so grossly out-of-proportion (translation: so damn overweight in all the wrong areas) it's pathetic.