Hi guys here is my second plant, it's growing fast and is probably about 1ft tall now, maybe a little less. It's growing straight up with some branching, the leaves are small and thin alternate. Kind of lobed wide at the base then turning into a spear shape, a few more veeeery subtle lobes until a half curved/half pointed end.
It looks a lot like Lambsquarters (Chenopodium album - I think they're called fat-hens in UK), so probably a member of genus Chenopodium or a Chenopodium album that looks different to me because it's growing in the UK?