So if it hasn't been said enough, absolutely get the Mod1 the very second you can. It's 200 fragments and some cores for a fair boost in performance. Extra stats, a bit more FP buff on her tiles, a little extra HP, and an improvement to the slowdown effect on the smoke.

The real problem is her 2nd skill is janky and not extremely practical. It's a little bit of a bonus, but not likely to make or break a fight. So yeah, the Mod2 isn't great. The mod 3 however, gives her a unique equipment that goes in the suppressor slot and is basically a suppressor with better stats (+5 EVA over normal) which helps her tanking ability somewhat. Whether this is worth it up to you, but definitely get the Mod1 at least.

The rest of this is basically the same song and dance where she has top class offensive buffs that continue to remain unmatched among SMGs, so you WILL likely continue to use her.

After literally years, M4 demonstrates WHY SHE IS THE HEROINE and becomes METAL GEAR.

She keeps all her old benefits but has 5 star multipliers and better stats now. This gets even better when Mod3 when she gets a unique that ups her firepower and ALSO gives her armour, so she can kinda tank in a pinch. Her buff tiles are ALSO slightly improved. Her mod 2 skill also tags enemies and enhances the mod skills of other Anti-Rain units.

The big thing however is the desperation mode. At mod2 onward, when 3 or fewer allied dolls are in battle (you can retreat 2 units to force this, or simply deploy her with a partial strength echelon), she pulls out the portable cannon and proceeds to deal hilarious damage that makes grenadiers wet their pants, as huge AoE blasts firing from every dummy. The blasts are kinda 100% accurate (the main hit can never miss, even at night, but the splash damage can. Its weird), and can partly crit (its complicated), and is meant to be a last ditch thing to save a fight under dire circumstances (of course, we instead abuse it). This is however, a doubled edged sword, as her RoF also goes down, so its possible for some enemies to slip by if you havent taken this into account.

Basically, Mod her first. She's pretty much priority #1 for modding.

The pinkhaired tryhard who is absolutely every bit as good as she says she is. 1 of the best sustained DPS ARs in the game, and can actually hit the RoF cap on her own. She can actually outDPS OTs-14 and 9A91 at night against up to moderately armoured opponents (moderate. Dont try to send her vs Hydras)

As a bonus, her mod skill ups her DPS some more by making her pull out ANOTHER gun and throwing extra attacks that do a % of her main damage, with more damage if paired with M4Mod.

Her mod skill however, does look absolutely retarded unless you're in her mod 3 form. Normally she's supposed to pull out another gun, but since her school skin and base sprite dont have that animation, she instead fires from her scope.

Modded version of M1911

A really expensive trash cleaner.

Basically when she pops smoke, she then goes Alvin York and blasts away 7 times for extra damage, hitting the farthest enemy and working her way closer to the front with every shot. If there are no closer enemies, she just keeps shooting that one until someone else has gotten closer (either because its dead and thus a new thing is closer, or something ran ahead of it).

Note that while the skill has an ICD of 1 second, she doesn't actually start blasting away until 3 seconds in due to the throw animation.

Modded version of G36

Distraught by the loss of her braid, she gets over it and discovers the TRUE maid was inside her all along. Or something like that.

Her stats are boosted a fair bit and the %s on her skill get a boost to 5 star levels. At mod 2, she gets a rider on her skill that boosts the Evade of stuff in her tiles, and also boosts her own RoF by 10% for every unit standing in her tiles (Max 2, yes it stacks multiplicatively). Yes, tile fuckery applies.

She does have the problem though that to fully make use of this skill, she needs units standing in the tiles, which weakens her flexibility a bit. Totally still fine for going gung ho and just blazing away in a static formation or if you can keep the formation such that stuff remains standing in the tiles though. Her performance is generally a bee's dick below that of AN94 (and makes a good match for AK12) in general use, but beats the Russians vs armored enemies.

Like any good HK product though, she's pretty expensive, so make sure you're sure about the investment and you have nothing else more important to work on (like AR team). Still, if you like the maid, definitely a thing to look at.

Technically has a combo thingy with Springfield, but it falls under "I guess it exists?" Yeah, I dunno what they were thinking.

Modded version of M14

What's there to say? Blood for the blood god, etc.

She gets bigger %s on her self buff and on Mod2 she buffs her own crit damage. You really want, if possible, to get that Oath ring on her for the extra stats at Mod3. While the new skill %s seem low, combined they pretty much exceed Lee Enfield's self-boost and part of it is a passive. It retains all her old advantages, but just embiggens the numbers a bit. Basically, she can provide IWS-level DPS (overall, not per shot) while maintaining her high (for an FP rifle) RoF, making her very efficient. Generally rated "probably 1 of the best mods to work on after you're done modding AR team" by older servers.