The best thing would be to take care not to bother them. Let them bear the struggle by themselves. They WILL take care to ask you something in case they need, don't worry. However, if you feel the need to communicate with them and realize this can motivate them enough, then you can write them individual messages. Usually, a weekly significant and useful for them group letter would be more than enough. To tell you a secret, I rarely receive a weekly letter from my upline.
