practical dress - any naice bargains about?

[Runnerd]

Could anyone help suggest something for me to wear to a christening in a couple of mths time?

I haven't bought any new clothes since ds was born and I'm lacking in things that make me feel nice and fit my post baby shape.

Tbh I've been very lucky and I'm not carrying too much extra weight anymore but my pre-baby clothes were for someone with a super flat tummy and a bit of a chest (ok only a b/c cup but it was something to work with). I just don't feel that great in the dresses I used to love with my wobbly mum tum and deflated balloon a-cups.

Also I don't want to spend too much. I'm still on mat leave so money is tight. Maybe £100 tops (but preferably less) anyone any ideas?

I'm 5'5 ok legs, flat chest, bit of tum wobble. Must be comfortable for baby wrangling in (although not bfing)

Thanks in advance!