Technically it has 1, and soon to be 2, in line (next generation). But when has a younger sibling having kids ever stopped the push for an heir to??? Joachim had kids first, was still a push for Fred. Elena and Cristina had kids first, but still a push for Felipe. Anne had kids first and so on. Its expected an heir will have children unless unable to (like with Baudouin).
But the only talk about babies was at the time engagement/marriage when they said they were thinking to wait a few years. Most people took that to mean 3. They were married for 3 in November, so now people are anxious.
There is also the fact they both said they want a large family. She is 32. If they want a few, and don't want to push into her 40's, they should start. If she got pregnant now, she would be 33 when it is born.
She is right on path with Jetsun.. Jetsun had been married for 3 1/2 years when she got pregnant with Jigme. But she is also 26.