It all depends what your plans are.

If you're going to breed, then no I wouldn't do it simply because your girl is nearly breeding size for being a young girl(my min on a young girl = 1500, 1200 for a girl who has laid a few clutches already). Though some people do breed at 1200, but I personally wouldn't. Then the fact that the Lesser Pastel girl is eating mice and is only 700g, to get her up bigger to breed is going to take quite awhile longer than if she was eating rats. There are many methods you can try but in the end some just don't switch.

This is all your decision, but I've found it that 95% of the time when a person is asking about doing a trade it's because they've already made up their mind and they want to justify a reason to switch. I personally wouldn't do the trade, but it's your call.