Canto 2 -
Ayodhyā-kāṇḍa
Chapter 44: Sumitrā Consoles Kausalyā
Text 2.44.19

कुशचीरधरं देवं गच्छन्तमपराजितम्।
सीतेवानुगता लक्ष्मीस्तस्य किं नाम दुर्लभम्॥

kuśa-cīradharaṁ devaṁ gacchantaṁ aparājitam
sītevānugatā lakṣmīs tasya kiṁ nāma durlabham

kuśa-cīradharam = wearing the garment of an ascetic; devam = the Lord; gacchantam = and He is going [to the forest]; apara-ajitam = He cannot be conquered by others; sītā = Sītā; iva = like; anugatā  = has followed; lakṣmīḥ = the prosperity of rulership; tasya = for Him; kim = what; nāma = indeed; durlabham = is impossible.

Like the prosperity of rulership, Sītā has followed the Lord. He cannot be conquered by others and He is going [to the forest] wearing the garment of an ascetic. What indeed is impossible for Him?

Sītevānugatā lakṣmīḥ indicates that the prosperity of ruling the kingdom does not accept anyone other [than Rāma].