Sorry for the late reply, here is a list of groups around the area.
Monday
Chepstow Methodist church parent and toddler group, Chepstow mon/tue/wed/fri - 10.00 to 11.15
Devauden Mother and Toddler Group, 10.00 to 12.00, at the Village Hall
Baby rhyme time at Monmouth Library - 10.30 to 10.50
Whirlykidz mother and toddler session - 10.00 to 12.00
Tuesday
Chepstow Methodist church parent and toddler group, Cheptow mon/tue/wed/fri - 10.00 to 11.15
Cylch Ti A Fi Baby/toddler group at Chepstow Library - 10.15 to 11.15
Tutshill baby/toddler group - 9.45 to 11.30
Dads can project play free play sessions at Whirlykidz Tue - 10.00 to 12.00
The tintern tots at tintern village hall from 10.30 to 11.30 (babies welcome)
Llanishen village hall 10.00 to 3.00, there is a mother and baby/ tots group. It includes a bouncy castle and soft play area, (the smaller babies tend to go in the morning)
Mini acorns toddler group, Bulwark - 1.00 to 3.00
Wednesday
Chepstow Methodist church parent and toddler group, Chepstow mon/tue/wed/fri - 10.00 to 11.15
Sedbury active tots at Sedbury village hall - 9.00 to 10.30
St Arvans baby toddler group, St Arvans memorial hall - 10.00 to 12.00
Active toddlers at Rivers children centre, Lydney - 1.00 to 2.30
Thursday
Baby rhyme time at Chepstow library - 2.15 to 2.45
Stroat at the evangelical church on the main road. Thursdays 10.00-12.00
Shirenewton toddler group, the rec hall - 1.30 to 3.00
Raglan Baby and Toddler Group at the Baptist Fellowship Rooms - 9.30-11am
Friday
Wiggle and Giggle at Chepstow Leisure Centre at 10.00 to 11.55, this includes bouncy castle, soft play and mini trikes (I think you can also use the swimming pool included in the price)
Bounce and rhyme at Lydney library - 11.00 to 11.30
Story time at Chepstow library - 10.15 to 10.45
Chepstow Methodist church parent and toddler group, Chepstow mon/tue/wed/fri - 10.00 to 11.15
Sunbeams toddler group at Monmouth Methodist church - Fridays at 10.30 to 12.00
Chepstow Methodist church parent and toddler group, mon/tue/wed/fri - 10.00 to 11.15
Dads can project free play sessions at jngle madness, Caldicot 1.00 to 3.00