On-device neural network tuning is essential for adapting pre-trained models to individual users and environments while preserving data privacy. However, ultra-low-power edge devices face significant computational and memory constraints that make training challenging, particularly for Transformer architectures. This work introduces a framework enabling efficient on-device training on RISC-V hardware, achieving significant improvements through Low-Rank Adaptation, including 23% dynamic memory reduction and 15x parameter reduction compared to standard backpropagation.