It can be done. I'm just hoping you, Patsfan73, are ready to be the one to do all the legwork, because there will be a lot, and it seems like your friend doesn't even know where to start. Honestly, I'd lower her expectations, and quickly.

My advice if she still wants to pursue this: it's generally easier to get hotel awards than flight awards, so encourage her to sign up for cards with open-ended rewards now—I'm thinking the 50k Chase Sapphire, Chase Ink, or the American Express Membership Rewards cards (green and above, usually gold has good bonuses)—and have her sign up for hotel cards in six months, at which point she can cancel her airline cards if Chase wants her to without losing her bonuses.

After she has all her points, she can see if she can find any award seats for two people. If she can, she can transfer her credit card points to an airline program. If not, she can transfer everything to a hotel program and look for a cheap flight on vayama.com. $1500-2000 for two rt tickets to Paris and hotels paid leaves her $1000-1500 for food and attractions, which is pretty good.

On the topic of companion certificates, Lufthansa's card gives you a free companion ticket if you buy one ticket in H economy. I haven't tried to use it, and I don't believe Lufthansa's credit card mileage bonuses are as great now as they have been in the past, but you'd have to pay for the ticket to get the free companion, anyway, so it shouldn't be a big deal. Also, LH's card is issued by Barclays, so it won't compete for your credit with cards from other issuers.