One thing to remember about your estate plan is that it is not set in stone. This means that if you change your mind later about how you have arranged things for a particular beneficiary, you can make a revision in most cases although this is not something you should procrastinate on if you do decide to make changes.
One common solution for dealing with a beneficiary who may not manage an inheritance responsibly for any reason is creating a trust. With a trust, you can specify when distributions are made. You can even leave the decision about when to make those distributions up to a trustee, the person who manages the trust. In complicated family situations, it may be best if this trustee is a bank or an attorney rather than a family member.
There are even situations in which you might want to disinherit a probable beneficiary altogether. If you decide to do this, you may need to specifically acknowledge this in the estate plan as well as include a reason why to reduce the likelihood of a successful challenge to the disinheritance.
An attorney may help you determine the right approach in your estate planning when you have complex family situations that involve difficult relationships or beneficiaries. The attorney may also be able to help in creating documents that use legal language correctly and reduce the likelihood of ambiguity that could lead to a misinterpretation of your intentions.