Reasoning LLMs under fixed token budgets often commit before verification finishes, or spend the budget on deliberation that never reaches a final answer. Existing inference-time controllers regulate reasoning length, which does not indicate whether the current prefix is ready to be finalized. We introduce ParentingLLM, an inference-time controller that paces reasoning maturity, defined as the prefix’s readiness to commit given the remaining budget, against a user-specified target schedule, without fine-tuning the underlying LLM. The maturity estimate combines consumed budget with a forked forced-commit probe; the controller injects Wait when the estimate runs ahead of the schedule and Hurry when it lags. On MATH-500, GPQA-Diamond, AIME 24+25, and GSM-Hard with three Gemma-4 models and Qwen3.5-9B, ParentingLLM improves over prior inference-time baselines, with the largest gains on AIME 24+25 under a tight budget (-22.6 burst rate, +4.0 to +7.3 accuracy at B=1024).