LLPM, you know fertility doesn't really start to decline until after 30, and it' a pretty slow decline in the early 30s, meaning there's still a lot of fertility at that point. So your sister has a good 10 years to TTC before the experts indicate it may get significantly harder (many people still get pg without a problem in the late 30s, but there is a definite difference between the early and late 30s). I wouldn't be worried! (the husband's age is generally not a factor)
It's a balancing act. On one hand, there is never a perfect time to have kids. On the other hand, there are bad times to have kids! What is a good enough time depends on the person, I think.
Also, my chart is so weird. I discarded my CD 9 temp, but if I count it, it gives me dotted lines for O on CD 8. Please tell me I didn't O then! I did sleep poorly CD 9 and 10, so I hope that's why my temps were high. I didn't even do an OPK on CD7+8 (I don't normally start until CD10), but I had no symptoms, non fertile CM, and I never O until CD18-19. What do you think? My Ovulation Chart