Learn Hardcore Chinese: wǒ xiǎng ràng tā xiān huí jiā.

It’s a causative verb. Pattern: X 让 Y V(…)= “X has/lets/makes Y do (something).” So 我想让她先回家 means “I would like to have/let her go home first.” 让 itself is neutral; whether it’s “let” (permission) or “make” (cause/instruct) depends on context and tone.

Does 想 mean “want” or “think” here?

Here 想 means “would like to / want to.” With 让 it expresses desire or intention.

Want: 我想让她先回家 = I’d like her to go home first.
Think: 我想她先回家了 = I think she already went home first. Without 让, 我想她… is usually read as “I think she…,” not “I want her to….”

Can I use 要 instead of 想? What’s the nuance?

Yes. 我要让她先回家 sounds stronger and more decided (“I will/I’m going to have her go home first”). 我想让她先回家 is milder and more tentative (“I’d like to…”).

Can I replace 让 with 叫 or 使?

叫 is common and colloquial: 我想叫她先回家 (natural).
使 is formal/literary and more often used for causing a result/state: 这件事使她很难过. You can see 使他离开 in formal writing, but for everyday speech here, prefer 让/叫.

Where does 先 go? Are there differences among 让她先回家 and 先让她回家?

All are natural, with slight emphasis differences:

我想让她先回家: default; she goes home before others/other actions.
我想先让她回家: first step (for me/us) is to let her go home, before we do other things. Both usually mean the same in conversation. Don’t say “让她回家先” in standard speech.

What’s the difference between 回家, 回到家, 回家去, and 回来/回去?

回家: go/return home (neutral).
回到家: emphasizes arrival (“return to home and reach it”): e.g., 回到家以后….
回家去: points outward/away from the speaker (“go back home”); acceptable but less common than just 回家.
回来 / 回去: come/go back relative to the speaker’s location. If the speaker is at home, say 回来; if not, 回去.

Why no preposition like 到 before 家?

With the directional verb 回, you can take a place directly: 回家, 回北京. Use 回到家 when you want to highlight the endpoint/arrival. Also, 到家了 is a set phrase meaning “(I/they) arrived home.”

In speech, is 她 “she” distinguishable from 他 “he”?

No. Both are pronounced tā (first tone). Only the written characters differ. Context clarifies in conversation.

Any pronunciation or tone-sandhi tips for this sentence?

Tones: 我 wǒ (3rd), 想 xiǎng (3rd), 让 ràng (4th), 她 tā (1st), 先 xiān (1st), 回 huí (2nd), 家 jiā (1st).
3rd + 3rd sandhi: 我想 is pronounced as wó xiǎng (我 becomes a 2nd-tone sound). The next syllables follow as normal: wó xiǎng ràng tā xiān huí jiā.

Can I drop 让 and say 我想她先回家 to mean “I want her to go home first”?

Avoid that. 我想她先回家 is typically understood as “I think she goes/went home first.” To express “want her to…,” use:

我想让她先回家, or
我要她先回家 (stronger).

How do I negate this?

Don’t want: 我不想让她先回家.
Didn’t intend/plan: 我没想让她先回家.
Imperative “don’t let…”: 别让她先回家.

How can I make it more polite or suggestive?

Add particles/softeners:

Proposal: 让她先回家吧。
Tentative opinion: 我想还是让她先回家吧。
Inclusive suggestion: 我们先让她回家吧。

Can I replace 她 with a name or plural?

Yes. Keep the word order:

我想让小王先回家。
我想让他们先回家。

Can I omit 家 and just say 回 or 回去?

In casual speech, yes, if context is clear:

她先回去。 = She’ll head back (not necessarily home).
她先回了。 = She headed back (often implies “home,” but less explicit). If you specifically mean “home,” 回家 is clearest.

Is 让 ever used for passive meaning?

Yes, in other sentences: 他让人骗了 = He got cheated (by someone). In your sentence it’s not passive; it’s causative: you want to have her do something.

Does 先 mean “first” like the number one?

No. 先 is an adverb meaning “first/firstly/before others/before other actions.” For ordinal “the first,” use 第一 or 最先:

她是第一个回家的。
她最先回家。

How would I say “I want her to go home earlier (earlier in time),” not “first”?

Use 早点/早一点 for “earlier”:

我想让她早点回家。 = I want her to go home earlier.