Welcome to HCM.
Your wife is having sub-chorionic haemorrhage of moderate size. This need not mean inevitable abortion
. This could resolve gradually. Your wife needs to take a few precautions, such as do not exert too much, try to have bed rest
as far as possible, drink plenty of water and eat fresh fruits so as to prevent stool from getting harder resulting in straining at passing stool, which increases the possibility of renewed bleeding. More over since it is Twin pregnancy
the risk is doubled.
Wish you both all the best.