No growth on Mimosa #2, Planted her the same day as the others

I asked a similar question about a mutant plant a few months back - the community answer was a massive 'let it grow' It was weird shaped, it popped with a seed helmet head, it grew slower, flowered slower. But it also got fucking massive and was a great learning experience. Give it a few weeks and if it is shit, bin it, but always give them the benefit of the doubt unless it is completely mangled - the weird ones might just surprise you.