DVC is best for people with a plenty of spare cash. Over the long haul, its UNLIKELY to actually save you money. There are a number of reasons for this...offsite or a value is often cheaper. DVC members usually find ways to go more often or spend more money, they decide one bedrooms are WAY nicer than studios (I would never buy to stay in DVC studios), without a hotel bill, they go to dinner a little more often, they might splurge and bring friends (not necessarily on the points you are discussing, but you might find yourself adding on in order to bring Grandma and Grandpa) - its the psychological part about DVC ownership. You may end up losing points over time - having to cancel last minute, or maybe a pandemic hits.
With young kids, there are always more expenses on the horizon - you get done with daycare and its dance. Traveling basketball. Saving for college. Car insurance for teens (!!!). Private school tuition. $2000 for the class trip. (I have two in college right now....well, when they get back to school after whatever is going to happen, so I'm a little weighted towards those final years). Add in saving for your own retirement, being able to replace the washer and dryer and furnace, having savings set aside if you spend three or six months out of work....I'm saying this because you used the word afford and made it sound like things were relatively tight in your budget, but these are things to think about in the overall decision. By putting money into DVC, what are you going to be saying no to? What instances of bad luck might hit that made you regret not having that cash in the bank instead of tied up in a timeshare?
Now, its also possible that you are looking at a future where your income will be increasing or expenses decreasing - maybe your own student loans are about to be paid off. Maybe your career is one that is very stable with a fairly predictable career trajectory that includes salary increases. You are pretty sure you will be made partner in a year.....that sort of thing. Its also possible that you are using afford to mean "make different choices," and so your use of afford does not mean "if we go for one bedrooms, we will not be able to replace the transmission on the car when it goes" and instead means "if we go for one bedrooms, I might have to get rid of some of my large stock portfolio to make the purchase." I don't know and can't tell, so don't read this as a value judgment, just as advice to look at your entire financial life and goals, not just
Disney vacations, when making this decision.