In California the executor could file a petition for final distribution of the estate 4 months after the executor was granted "letters testamentary" (officially appointed) by the Court. Every state varies, but 7 months does not seem like an unreasonable period of time. There may be tax issues or other issues that the executor needs to deal with that could make him need more time to complete the probate. If your step-daughter has a good relationship with her step-father, I suggest that she ask him how much longer he thinks he will need.
The information you obtain at this site is not, nor is it intended to be, legal advice. You should consult an attorney for individual advice regarding your own situation.
Once an executor is appointed by the probate court, his only duties are to complete an inventory and appraisement, complete the distribution contemplated by the will, and file a final inventory and close the estate. In Texas, the probate process is generally inexpensive compared to other states, but can be a bit slow. An estate often takes 12-18 months to be probated and closed, and that is usually due to the time it takes for an executor to get the inventory and appraisement completed. Many practitioners would require that be done before any distribution be made, although in a case like this, that seems unnecessary. If the daughter is concerned that the terms of the will are not being honored, she may make application to the Court for a distribution.
The Texas Probate Code gives the Executor 15 months before a distributee (your step daughter) could force an accounting and distribution.