I discovered something kinda neat (while everyone else probably already knows this, it was a neat discovery for me
) My decision to deviate from the norm (with a matriarch instead of a patriarch) has yielded unexpected fruit.
My first addition to the household was good ole' Agnes, and a worthy addition she has been. I set her to work on cranking out paintings, and managed to SuperMax the skill somewhat quickly. Pretty good for a non-immortal getting on in the years. This gave me my first masterpiece portrait for my matriarch, Lilith, and ensured at least a couple more masterpiece additions before Grimmy comes to gather her up.
Christopher Steele ended up being the baby-daddy, and I set him about his task quickly. The first born immortal-to-be, Belial, was born well before the first week was out. And here's where I had two fortunate strokes of luck. First of all, the good camera turned up at the consignment store (no book though). I managed to get photos of Lilith and Belial both taken by Christopher...so they should skyrocket when he joins Agnes in Grimmy's fold. The second stroke of luck was that Agnes managed to squeeze off her 5 masterpieces half way through Belial's toddler years. It only took a couple attempts to his masterpiece portrait in the museum before he aged up. And his was in the museum a day before Lilith's was.
Here's where the discovery comes in: I decided for her to continue to have children. I don't think Agnes is going to hang, so I want to have an artistically inclined mortal around to paint a masterpiece for Lilith's golden years. After having a second child, I decided that a third child, working a rabbit-hole job, would help add much needed finances to purchase properties for the second generation. The day before Lilith was due to age up, Christopher fulfilled the duties of "mortal concubine" once more. The next day, I get the "It's Lilith's birthday!" message. A couple hours later she's prego.
Apparently, sims don't age up if their in the motherly way. This gave me a couple of precious extra days to work on her requirements. Days she needed, since she started at young adult instead of a toddler. And all done without cheating.