Hello they're a bit leggy if you have space and can handle them re pot a bit deeper,as soon as 2 leaves show take out of heat and put in a cooler place,lettuce only needs initial heat to germinate after that they grow quick ,I use to sow thousands of lettuce January till October ,they went into blocks on a Friday then into the propagating house covered with 8x4 polystyrene sheets the polystyrene sheets were removed on Monday morning with a full germination (if there was any miss sown or failed blocks there was hell to pay )they were planted 10 days later jezza