According to Rambam, in H. Issure Biah 21:8, he states that:
נָשִׁים הַמְסוֹלָלוֹת זוֹ בָּזוֹ אָסוּר וּמִמַּעֲשֵׂה מִצְרַיִם הוּא שֶׁהֻזְהַרְנוּ עָלָיו שֶׁנֶּאֱמַר (ויקרא יח ג) "כְּמַעֲשֵׂה אֶרֶץ מִצְרַיִם לֹא תַעֲשׂוּ". אָמְרוּ חֲכָמִים מֶה הָיוּ עוֹשִׂים אִישׁ נוֹשֵׂא אִישׁ וְאִשָּׁה נוֹשֵׂא אִשָּׁה. וְאִשָּׁה נִשֵּׂאת לִשְׁנֵי אֲנָשִׁים. אַף עַל פִּי שֶׁמַּעֲשֶׂה זֶה אָסוּר אֵין מַלְקִין עָלָיו. שֶׁאֵין לוֹ לָאו מְיֻחָד וַהֲרֵי אֵין שָׁם בִּיאָה כְּלָל. לְפִיכָךְ אֵין נֶאֱסָרוֹת לִכְהֻנָּה מִשּׁוּם זְנוּת וְלֹא תֵּאָסֵר אִשָּׁה עַל בַּעְלָהּ בָּזֶה שֶׁאֵין כָּאן זְנוּת. וְרָאוּי לְהַכּוֹתָן מַכַּת מַרְדּוּת הוֹאִיל וְעָשׂוּ אִסּוּר. וְיֵשׁ לָאִישׁ לְהַקְפִּיד עַל אִשְׁתּוֹ מִדָּבָר זֶה וּמוֹנֵעַ הַנָּשִׁים הַיְדוּעוֹת בְּכָךְ מִלְּהִכָּנֵס לָהּ וּמִלָּצֵאת הִיא אֲלֵיהֶן:
Lesbian relations are forbidden. This is "the conduct of Egypt" which we were warned against, as [Leviticus 18:3] states: "Do not follow the conduct of Egypt." Our Sages said: What would they do? A man would marry a man, a woman would marry a woman, and a woman would marry two men.. Although this conduct is forbidden, lashes are not given for it, for it is not a specific prohibition and there is no intercourse at all. Therefore such women are not forbidden to marry into the priesthood as zonot, nor does a woman become prohibited to her husband because of this, for this is not considered harlotry. It is, however, appropriate to give them stripes for rebellious conduct because they performed a transgression. A man should take precautions with his wife with regard to this matter and should prevent women who are known to engage in such practices from visiting her and her from visiting them.
Moreover, according to an answer to this post on the Judaism StackExchange, Rambam is echoing the earlier statements found in the Sifra and Talmud. For instance, Sifra, Ahare Moth 8:8 states:
"כמעשה ארץ מצרים וכמעשה ארץ כנען לא תעשו", יכול לא יבנו בנינים ולא יטעו נטיעות כמותם? תלמוד לומר "ובחוקותיהם לא תלכו" – לא אמרתי אלא בחוקים החקוקים להם ולאבותיהם ולאבות אבותיהם. ומה היו עושים? האיש נושא לאיש והאשה לאשה. האיש נושא אשה ובתה, והאשה נישאת לשנים. לכך נאמר "ובחוקותיהם לא תלכו".
"As the deed of the land of Egypt and as the deed of the land of Canaan, you shall not do," I might think they should not build or plant as they do; it is, therefore, written (Joshua 11:15) "and in their statutes you shall not walk." I have proscribed for you only those statutes which were instituted for them and for their forefathers and for the fathers of their forefathers. What did they do? A man would wed a man, and a woman, a woman. A man would wed a woman and her daughter, and a woman would wed two — wherefore Scripture states "and in their statutes you shall not walk."
So taking this into account, Rambam states that it is appropriate to give them stripes for rebellious conduct. Then, I went to research again the concept of giving stripes, and according to the Jewish Encyclopedia article wrriten by a counselor Lewis N. Dembitz, D.H.L. and a Jewish scholar, professor and theologian, Dr. Wilhelm Bacher, Ph.D., stripes as a corporal punishment may not be inflicted more than 40 times for a punishment. This comes directly from Deuteronomy 25:3 which states:
אַרְבָּעִ֥ים יַכֶּ֖נּוּ לֹ֣א יֹסִ֑יף פֶּן־יֹסִ֨יף לְהַכֹּת֤וֹ עַל־אֵ֙לֶּה֙ מַכָּ֣ה רַבָּ֔ה וְנִקְלָ֥ה אָחִ֖יךָ לְעֵינֶֽיךָ׃
but the judge must not impose more than forty lashes. If the guilty party is flogged more than that, your fellow Israelite will be degraded in your eyes.
From this, the question then becomes: since the word used here means essentially "brother" (אָחִ֖יךָ), which seems to be used mainly in masculine contexts (although some translations use the word "peer", instead of "brother" which is a little strange given that according to the Wiktionary, the word being used here is a singular form of אָח (ách) with second-person masculine singular personal pronoun as possessor), how appropriate is it to prescribe such a punishment to a woman (also taking into account that Rambam previously seemed to have believed in his Commentary to the Mishnah (Sanhedrin 7:3) that even according to Rabbinic Law, no punishment should be given? Additionally, since the number 40 is a commonly used cultural idiom throughout the Ancient Near East, and was certainly in use when the Deuteronomy was written down, does the number 40 in this context for this punishment, refer to a really long time period i.e. they are to be given stripes for a very long time period so don't go beyond a very long time or you may lose respect for them, or is it specifically 40 stripes in a more literal way? I know that in the Talmud, the number has been reduced to 39 stripes as the maximum just in case so that no one goes above the limit (Mak. 22a), but it doesn't conclusively indicate that 40 stripes wasn't metaphorical and the actual theoretical limit could potentially be higher in my view.
All in all, I'm generally confused as to what the punishment for lesbianism is now, because of the word "brother" being used when stripes are to be given and also the length/quantity of the punishment. If someone could potentially clarify this, I'd greatly appreciate it. What are the exact specification that should be used for this punishment and also what type of whip should exactly be used for this? Alternatively, can someone explain why Rambam says that they're to be striped if the word being used is masculine and the number/type of tool to be used for this?