It's a big progress if I became able to ○○ even if it's just a little.
It's a big progress for me if I became able to speak English even if it's just a little.
It's a big progress for me if I became able to cook dishes even if it's a little.
「少しだけど〜ができるようになったのは大きな進歩です」は英訳すれば、「It's a big progress if I became able to ○○ even if it's just a little.」になります。
○○のところに(英語)の名詞に置きます。「自分にとって 」を伝えたいの場合、progressの後に「for me」を書けます。
例えば、「英語の話せる」の場合、「It's a big progress for me if I became able to speak English even if it's just a little.」になります。
「料理ができる」の場合、「It's a big progress for me if I became able to cook dishes even if it's a little.」
ご参考になれば幸いです。