I’m not sure you will find an entire nuptial Mass on video. That would be probably an hour long at least!
*]Option #1: Liturgy of the Word (Readings, homily) followed by exchange of vows
*]Option #2: Liturgy of the Word (Readings, homily) followed by exchange of vows plus Liturgy of the Eucharist (presentation of gifts, consecration, great Amen, kiss of peace, reception of the Eucharist, etc.)
If you are familiar with the Mass, then you already have a good idea of what a wedding/nuptial Mass will be like. The main difference between a nuptial Mass and a regular Mass is the exchanging of vows, which you would be doing whether or not you did the full Mass or the abridged service with just the Liturgy of the Word.
So, just imagine exchanging vows after the homily but before the gifts are brought up to the altar.
When one party is Catholic and the other is not, many priests will recommend not doing the Mass because of the sign of disunity it creates by having only one spouse receive Communion while the other does not. That’s a legitimate concern.
However, if you will both be Catholic by the time of the wedding, I would definitely encourage the full Mass. What better context to be joined as one flesh than the celebration of the Eucharist where we get to be so intimately untied with our Lord?
Much of my family is either Protestant or lapsed Catholic, but for us, that was, frankly, their problem. We never even considered not having a nuptial Mass. We’re both cradle Catholics, though.
Nonetheless, you definitely want to be sensitive to your fiance’s concerns. Perhaps the graces she receives in the Sacraments she receives on Easter Vigil will hel alleviate her misgivings. It’s good that your trying to be proactive.
BTW, my wife had a big poofy dress with a 12 foot train and she still knelt just fine.